Philomedes assimilis Brady 1907

“Philomedes assimilis

(Plate I., figs 16-21. Plate II., figs. 1-6.)

Shell of the female seen from the side oblong, subcircular, height equal to two-thirds of the length, anterior extremity sharply angulated below at its junction with the wide truncated rostrum, posterior sloping steeply and forming a somewhat rounded, prominent angle at its ventral end; dorsal margin strongly arched, highest in the middle, ventral evenly but less strongly convex, terminating in front in a deep subrostral sinus and behind in an obtusely angular process. Seen from above the outline is oblong, ovate, twice as long as broad, greatest width situated in the middle, anterior extremity obtusely pointed, posterior produced and mucronate, lateral margins evenly arcuate. The shell of the male much longer in proportion to the height, rostrum and subrostral sinus much less pronounced, posterior extremity more narrowed and having a larger and more rounded ventral prominence; the squamous, marginal laminae of the rostrum are marked with numerous hair-like striae and are closely punctuated. The limbs and appendages do not present any special specific characters, but the hairs at the base of the claws of the post-abdomen of the male are more than usually conspicuous. Length of the female, 1.8 mm.

The stations at which P. assimilis was taken were all in the Winter Quarters: –

September 30, 1903 – No. 12 hole, D. net 246.

Hut Point – September 13, 1902, D. net.

Hut Point – February 13, 1904, D. net 264.

10 Fathoms, March 19, 1902.

November 28, 1902, D. net.

May 23, 1902, and February 13, 1904.

12 Hole, D. net, September 8, 1903.” (Brady 1907, p.5)

Philomedes assimilis Brady

Philomedes assimilis Brady, 1907:5, pl. 1: figs. 16–21; pl. 2: figs. 1–6.—Müller, 1908:87, pl. 6: figs. 9–17; pl. 7: figs. 14–16; 1912:26 [key], 31.—Scott, 1912:586.—Skogsberg, 1920:352, 367, 413.—Barney, 1921:178.—Lofthouse [part], 1967:143.—Kornicker, 1971:186, fig. 14.

Philomedes antarctica Brady, 1907:5, pl. 3: figs. 1–10.—Kornicker, 1971:189, fig. 15.

HOLOTYPE.—None selected.

SYNTYPE LOCALITY.—Winter Quarters, McMurdo Sound, Ross Sea, Antarctica.

MATERIAL.—USNM 125822, gravid ♀; USNM 125823, 13 specimens, mostly juveniles, no gravid ♀ ♀; USNM 125844, gravid ♀; USNM 125845, 14 specimens including gravid ♀ ♀ and juveniles; USNM 125846, 5 adult specimens; USNM 125847, 1 N–1 ♂, length 1.75 mm, height 1.11 mm; USNM 125848, gravid ♀; USNM 125849, adult ♀; USNM 125854, gravid ♀; USNM 125855, 23 specimens including 1 adult ♂, several adult ♀ ♀ and many juveniles; USNM 125856, gravid ♂; USNM 125857, 1 gravid ♀ + 2 adult ♀ ♀; USNM 125858, gravid ♀; USNM 125859, 2 juveniles; USNM 125861, gravid ♀; USNM 125862, 1 gravid ♂ + 5 juveniles; USNM 125863, 1 N–1 length 1.81 mm, height 1.13 mm; USNM 125972, gravid ♀; USNM 126094, gravid ♀; USNM 126097, gravid ♀; USNM 126098, gravid ♀; USNM 126099, gravid ♀; USNM 127491, gravid ♀; USNM 126100, 7 specimens including 2 gravid ♀ ♀; USNM 127492, 1 gravid ♀ + 3 adult ♀ ♀ + 4 juveniles; USNM 127497, gravid ♀; USNM 127499, 1 juvenile ♀, length 1.61 mm, height 1.11 mm + 1 adult ♂ + 1 juvenile; USNM 126122, gravid ♀; USNM 126123, adult ♀; USNM 126225, gravid ♀; USNM 136167, adult ♀; USNM 136168, 6 specimens; USNM 136179, adult ♀; USNM 136180, 8 specimens including 3 adult ♀ ♀ and juveniles; USNM 136570, adult ♀; USNM 125970, 1 juvenile ♀, length 1.37 mm, height 0.95 mm; USNM 136571, 1 juvenile, length 1.43 mm, height 0.90 mm; USNM 136572, 9 adult ♂ ♂; USNM 136573, 20 gravid ♀ ♀; USNM 136574, 257 adult ♀ ♀ and juveniles; USNM 136578, 2 adult ♂ ♂ + 7 gravid ♀ ♀ + 41 adult ♀ ♀ and juveniles; USNM 136582, adult ♀; USNM 136584, adult ♀; USNM 138016, 1 adult ♀; USNM 138017, 2 gravid ♀ ♀ + 18 adult ♀ ♀ + 12 juveniles; USNM 138157, 1 adult ♀; Hero station 69–24, 1 juvenile returned to Chile + 1 adult ♀ (USNM 138164); Hero 69–37, 1 gravid ♀ returned to Chile; USNM 138652, 1 adult ♀ without eggs; USNM 139147, 2 gravid ♀ ♀ + 1 juvenile; USNM 139148, 1 N–1 ♂, length 1.76 mm, height 1.24 mm, + 3 specimens; USNM 139149, 1 gravid ♀ + 4 juveniles; USNM 139150, 1 specimen; USNM 139151, 1 specimen; USNM 139152, 1 gravid ♀; 2 specimens from TA–D51 returned to Dr. Patrick M. Arnaud.

Through Dr. K. McKenzie and Miss Rosemary L. Sayers of the British Museum, I received the following Discovery material which had been reported upon by Patricia Lofthouse (1967:143):

1. A vial containing the following label: “Philomedes assimilis Brady, Sta 105, off Antarctic coast, Res. 192. BANZARE, 1966. F.20.50.” The vial contains 9 specimens of P. assimilis, including 2 or 3 adult ♀ ♀ plus juveniles.

2. Two slides, each bearing the following label: “Philomedes assimilis ♂ B.A.N.Z.A.R.E. Res. 192, off Antarc. coast, from 1966. F.20.50.” One slide bears two valves, the other appendages. These two slides contain an adult ♂ of P. assimilis. This sample is from station 105.

Through Mr. David C. Lee of the South Australian Museum, I received the following material which had been correctly identified by Lofthouse (1967) as Philomedes assimilis.

1. A vial containing the label, “1741, 4–9–12, Adelie Sound” and 5 specimens of P. assimilis.

2. A vial with the label, “Coll. A 1784” and 2 juveniles of P. assimilis. I believe that these specimens are those listed as coming from Commonwealth Bay by Lofthouse (1967:143). Both this sample and vials 1 above and 7 below were probably collected on the Australasian Antarctic Expedition, 1911–1914.

3. A vial with the label, “Res. 192, Philomedes assim” and 19 specimens of P. assimilis. This residue is from Discovery station 105.

4. A vial with the label, “Res. 196 Ostracoda” and 1 juvenile ♀ of P. assimilis. This residue is from Discovery station 105.

5. A vial with the label, “Res. 231 Ostracoda” and 1 adult ♂ of P. assimilis. This residue is from Discovery station 105.

6. A vial with the label, “Res. 140 Ph. assimilis” and a gravid ♀ of P. assimilis. This residue is from Discovery station 106.

7. A vial with the label, “Res. 68” and 2 juveniles of P. assimilis. This residue is from station 1783 (see 2 above).

8. A vial with the label, “DRL 13–2–31, 105, 163 m” and 7 specimens of P. assimilis including 1 adult ♂ and 1 gravid ♀ with 12 eggs. This sample is from Discovery station 105.

USNM LOCALITIES.—USNM 125822, 125823 from Eltanin Cruise 12, station 1003; USNM 125844–125846 from U.S. Navy Expedition, station 104; USNM 125847 from U.S. Navy Expedition, station 234; USNM 125848, 125849 from Deep Freeze II, USS Glacier, station 19; USNM 125854, 125855 from Deep Freeze III, USS Glacier, station B1–12; USNM 125856, 125857 from Deep Freeze II, USS Glacier, station 1; USNM 125858, 125859 from Deep Freeze III, Burton Island, station 5; USNM 125861, 125862 from Deep Freeze III, USS Glacier, station B1–13, USNM 125863 from Deep Freeze III, USS Atka, station 25; USNM 125972 from Deep Freeze IV, USCGC Northwind, station 8; USNM 126094, 126097-126100, 127491, 127492, 127497, 127499 from Deep Freeze I, USS Edisto, stations 5, 6, 8 combined; USNM 126122, 126123 from Eltanin Cruise 7, station 499; USNM 126225 from IWSOE, USCGC Glacier Cruise 2, station 0004; USNM 136167, 136168 from Octans, station AZ; USNM 136179, 136180 from Octans, station AH; USNM 136570 from Octans, station AG; USNM 125970 from Deep Freeze II, USCGC Glacier, station 20; USNM 136571 from Deep Freeze II, USCGC Glacier, station 22; USNM 136572–136574, 136578 from Eltanin Cruise 27, station 1896; USNM 136582 from Eltanin Cruise 32, station 2035; USNM 136584 from Eltanin Cruise 27, station 1870; USNM 138016, 138017 from Octans, station TAT: USNM 138157 from Deep Freeze IV, Edisto Cruise 23, sample TR 9, 10, 11; Hero 69–24 from station on XXIII Exp. Ant. Chile (includes USNM 138164); Hero 69–37 (includes USNM 138652) from XXIII Exp. Ant. Chile. USNM 139147 from station TA–L19; USNM 139148 from TA–D67; USNM 139149 from TA–14–2–1965.B; USNM 139150 from TA–12–2–1965; USNM 139151 from TA–D104; USNM 139152 from TA–D151.

DIAGNOSIS OF FEMALE.—Carapace with truncate posterior and angular caudal process, length 1.67 mm to 2.00 mm.

First antenna: 2nd joint with 5 or 6 bristles, 3 or 4 ventral, 1 dorsal, 1 lateral.

Second antenna: Endopodite 2-jointed: 1st joint with 5 short bristles; 2nd joint with 1 long and 3 short ventral bristles and 1 long recurved terminal bristle.

Mandible: Dorsal margin of basale with 1 proximal bristle, 2 near middle and 2 terminal.

Seventh limb: Each limb with 9 bristles, 5 distal, 4 proximal; 2 pegs present opposite terminal comb.

Furca: Each lamella with 10 claws.

Lateral eye: Small with 2 divided ommatidia.

SUPPLEMENTARY DESCRIPTION OF ADULT FEMALE (Figures 128–130).—Carapace size (Figure 131): USNM 125822, length 1.82 mm, height 1.23 mm; USNM 125844, length 1.89 mm, height 1.29 mm; USNM 125848, length 1.76 mm, height 1.25 mm; USNM 125849, length 1.81 mm, height 1.33 mm; USNM 125854, length 1.77 mm, height 1.29 mm; USNM 125856, length 1.83 mm, height, 1.28 mm; USNM 125858, length 1.91 mm, height 1.29, mm; USNM 125861, length 1.83 mm, height 1.26 mm; USNM 125972, length 1.79 mm, height, 1.22 mm; USNM 126094, length 1.83 mm, height 1.20 mm; USNM 126097, length 1.71 mm, height 1.32 mm; USNM 126098, length 1.90 mm, height 1.16 mm; USNM 126099, length 1.83 mm, height 1.26 mm (figured specimen); USNM 127491, length 2.00 mm, height 1.54 mm; USNM 127497, length 1.77 mm, height 1.37 mm; USNM 126122, length 1.87 mm, height 1.14 mm; USNM 126225, length 1.93 mm, height 1.09 mm; USNM 136167, length 1.86 mm, height 1.36 mm; USNM 136179, length 1.85 mm, height 1.33 mm; USNM 136570, length 1.96 mm, height 1.42 mm; USNM 136573, length 1.67 mm, height 1.34 mm; USNM 136582, length 1.96 mm, height 1.33 mm; USNM 136584 (not dissected) length 1.91 mm, height 1.30 mm; Discovery Residue 140, length 1.96 mm, height 1.35 mm: Discovery station 105, length 1.82 mm, height 1.37 mm; USNM 138157, length 2.00 mm, height 1.31 mm; USNM 138164, length 1.85 mm, height 1.34 mm; Hero 69–37 (Chilean collection), length 1.75 mm, height 1.31 mm; USNM 139147, length 1.91 mm, height 1.34 mm; USNM 139152, length 1.93 mm, height 1.28 mm (not dissected).

Eggs: USNM 125822, 9 eggs; USNM 125848, 14 eggs; USNM 125854, 5 eggs; USNM 125856, 9 eggs; USNM 125858, 9 eggs; USNM 125861, 11 eggs; USNM 125972, 10 eggs; USNM 126094, 6 eggs; USNM 126097, 11 eggs; USNM 126098, 10 eggs; USNM 127497, 12 eggs; USNM 126122, 3 eggs; USNM 126225, 7 eggs; USNM 136573, 11 eggs; Discovery Residue 140, 12 eggs; Hero 69–37, 5 eggs; USNM 139147, 6 eggs.

SUPPLEMENTARY DESCRIPTION OF ADULT MALE.—Carapace size (Figure 131): USNM 126572 (4 specimens, last 3 listed not dissected) length 2.23 mm, height 1.22 mm; length 2.21 mm, height 1.20 mm; length 2.14 mm, height 1.23 mm; length 2.24 mm, height 1.27 mm. Discovery Residue 231, length 2.21 mm, height 1.23 mm.

Parasites: USNM 136167 (adult ♀) with 1 choniostomatid ♀; USNM 136179 (adult ♀) with 1 choniostomatid ♀ and 4 ovisacs; USNM 138016 (adult ♀) with 1 choniostomatid ♀ and 7 ovisacs; USNM 138652 with 1 choniostomatid ovisac. A paradoxostomatid ostracod present in the region of the 2nd antenna of an adult ♀ from Discovery station 105 may be a parasite. Diatoms are attached to the carapace of an adult ♀ (USNM 136179) (Figures 129, 130).

The paradoxostomid ostracode mentioned above has been identified by McKenzie (1972:161) as Paradoxostoma cf. hypselum Müller, 1908. McKenzie suggested that the occurrence may indicate that some paradoxostomids parasitize benthic myodocopids. Elofson (1941, 1969:216) has observed Paradoxostoma, which usually feed by sucking plant juices, “… firmly sucking a dead polychaete, amphipod or similar object, suggesting that animal food is also used when available. G. O. Sars holds the same view (1865:92).”

REMARKS CONCERNING SPECIMENS REPORTED BY BARNEY (1921).—I did not examine the 10 specimens collected by the Terra Nova Expedition in McMurdo Sound, but as this is the type-locality for P. assimilis, it is probable that all or some of the specimens identified as P. assimilis by Barney belong to that species.

DISTRIBUTION.—This species has been collected only in the Antarctic region at depths of 9 to 876 m (Figure 132).

Philomedes assimilis Brady.—Lofthouse, 1967:143

HOLOTYPE.—Gravid ♀, specimen 1 herein, length 2.38 mm, F.20.53, collection of British Museum (Natural History).

TYPE-LOCALITY.—Discovery Cruise 1, station 58, in Hydrography Channel, a short distance southeast of Green Island, Kerguelen; water depth 50 m.

ETYMOLOGY.—This species is named after Patricia D. Lofthouse.

PARATYPES.—2 gravid ♀ ♀, 2 juveniles in alcohol, 1 complete freeze-dried specimen on slide. Two slides containing specimen dissected by P. Lofthouse. All specimens in collection of British Museum (Natural History). The specimen dissected by Lofthouse is from Residue 166, Discovery station 15, Kerguelen; other paratypes are from same sample as holotype.

Through Mr. David C. Lee, I received on loan from the South Australian Museum the following specimens which had been identified by Lofthouse (1967:143) as Philomedes assimilis:

1. A vial with the label, “Res. 197, Philomedes assimilis” and 1 gravid ♀ and 1 juvenile of P. lofthousae. This sample is from Discovery station 53.

2. A vial with the label, “DRS, 23–11–29, St. 15. 55 m” and 3 specimens of P. lofthousae. This sample is from Discovery station 15.

3. A vial with the label, “Res. 199 A” and 1 N–1 ♂ of P. lofthousae. This sample is from Discovery station 58.

4. A vial with the label, “DRL 22/12/30, St. 58, 50 m, Jar 2” and 5 gravid ♀ ♀, 1 adult ♀ without eggs, and 6 juveniles of P. lofthousae. This sample is from Discovery station 58.

Through Dr. K. McKenzie and Miss Rosemary L. Sayers of the British Museum (Natural History), I received the following material from the vicinity of the Kerguelen Islands, which had been identified as Philomedes assimilis Brady by Lofthouse (1967:143):

1. A vial containing the label, “Philomedes assimilis Brady, Sta. 58, Kerguelen, 22.2.30. BANZARE, 1966. F. 20.53” and 6 specimens of P. lofthousae, including 3 gravid females. This sample is from Discovery station 58.

2. Two slides, each bearing the label, “Philomedes assimilis ♀, B.A.N.Z.A.R.E. Res. 166—Kerguelen, 1966. F.20.51.” One of the slides bears 2 valves, the other slide bears appendages and eggs. The specimen is a gravid ♀ of P. lofthousae. This sample is from Discovery station 15.

NEW COLLECTIONS.—I received the following specimens from Dr. P. M. Arnaud collected by him in the vicinity of the Kerguelen Islands: 3 gravid ♀ ♀ plus 12 juveniles (USNM 139853) and 1 gravid ♀ and 2 juveniles returned to Dr. Arnaud, all from station Ker–D74; 1 juvenile ♂ (USNM 141101) from station Ker–D40.

DIAGNOSIS.—Posterior of carapace truncate; length 2.25–2.65 mm; surface with scattered bristles.

First antenna: 2nd joint with 5 or 6 bristles: 2 ventral (rarely 3), 2 dorsal, 1 or 2 lateral.

Second antenna: 1st endopodial joint with 6 bristles, 2nd with 4.

Mandible: Dorsal margin of basale with 6 bristles.

Seventh limb: Each limb with 30 or 31 bristles; 2 pegs present opposite comb.

Furca: Each lamella with 10 or 11 claws.

Lateral eye: Small with 2 or 3 ommatidia.

DESCRIPTION OF FEMALE (Figures 171–176).—Carapace with prominent rostrum with minute protuberance on rounded interior corner, broad incisur, and truncate posterior (Figures 171; 172a,c,d; 173).

Ornamentation: Carapace smooth with scattered single bristles on lateral surface and more closely spaced bristles along margin of rostrum and ventral margin (Figure 173e,f).

Infold (Figure 172c,d): Infold broad along anterior and posterior of shell, narrower along ventral margin; infold on rostrum with 29 or 30 bristles, mostly branching; minute bristle present on infold posterior to incisur; anteroventral part of infold with about 15 striae and 19 to 22 spinous bristles forming row; posteroventral and posterior infold with about 137 bristles along raised list (bristles longer than usually present in this region); 7 to 10 bristles forming row present between list and posterior edge of caudal process; about 5 short bristles present inside posterior edge of caudal process.

Selvage (Figure 173): Lamellar prolongation with marginal fringe present along anterior, ventral, and posterior margins; prolongation with typical segmentation present along rostrum and incisur; long bristles present on prolongation below incisur.

Size (Figure 131): Mounted specimen under cover slip, Residue 166, station 15: valve length 2.37 mm, height 1.68 mm, left valve, length only 2.43 mm. Gravid ♀ ♀, Residue 192, station 105: specimen 1, length 2.38 mm, height 1.60 mm; specimen 2, length 2.65 mm, height 1.75 mm; specimen 3 (not dissected) length 2.25 mm, height 1.65 mm. Adult ♀, station 15, length 2.42 mm, height 1.73 mm. Gravid ♀, station 58, length 2.39 mm, height 1.62 mm. USNM 139853, length 2.34 mm, height 1.65 mm.

First antenna (Figures 172a,e; 174e): 1st joint with spines forming clusters along ventral margin and on lateral and medial surfaces; 2nd joint spinous, with 5 or 6 bristles, 2 ventral (rarely 3), 2 dorsal, 1 or 2 lateral; 3rd joint with 3 bristles, 2 dorsal, 1 ventral; 1 cluster of spines observed near terminal margin on medial surface; 4th joint with 5 spinous bristles, 4 ventral, 1 dorsal; surface of joint without spines; 5th joint with spines forming clusters on distal lateral surface; sensory bristle of 5th joint with 5 marginal filaments and tip consisting of 4 or 5 filaments; medial bristle of 6th joint about half length of sensory bristle of 5th joint and with short marginal spines except for 1 long proximal spine. Seventh joint: a-bristle spinous, about two-thirds length of sensory bristle; b-bristle with 1 proximal and 4 terminal filaments; c-bristle with about 2 proximal and 4 terminal bristles. Eighth joint: d and e-bristles bare, about same length as sensory bristle; f-bristle with about 3 proximal and 5 terminal filaments; g-bristle with 4 proximal and 4 terminal bristles. The distribution of bristles on the 2nd joint of 1st antenna of 4 specimens is tabulated below:

Second antenna (Figure 172f): Protopodite with abundant long hairs on dorsal margin and lateral surface near dorsal margin; short spines forming clusters present along ventral margin and on medial surface. Endopodite 2-jointed: 1st joint with 6 bristles, 5 proximal, 1 distal; 2nd joint with 1 long proximal bristle with long proximal and short distal marginal spines, 2 short distal bristles with short marginal spines, and 1 long recurved bare terminal filament. Exopodite: 1st joint with short medial bristle; bristle of 2nd joint reaching past 9th joint and with 11 spines near middle; bristles on joints 3 to 5 with ventral spines and no natatory hairs; bristles on joints 5 to 8 with natatory hairs, some bristles broken; 9th joint with 6 or 7 bristles; distal margins of joints 2 to 8 with combs of short spines; faint spines forming clusters present on medial surface of joint 2; small basal spines present on joints 2 to 6.

Mandible (Figure 172g): Coxale with spines forming clusters on surface; endite spinous, pectinate, with bifurcate tip, small bristle present near base. Basale: medial side with 6 short proximal bristles, 3 stout pectinate, 3 slender spinous; lateral side with 5 short spinous bristles near ventral margin (proximal of these with base on ventral margin); ventral margin with 3 spinous distal bristles; dorsal margin with 4 long spinous bristles, 1 near middle, 1 distal to middle (this bristle absent on right limb of 1 of 3 specimens examined), and 2 terminal; lateral and medial surfaces of joint with numerous spines forming clusters. Exopodite three-fourths length of dorsal margin of 1st endopodite joint, with 2 terminal bristles, inner bristle slightly longer, both with short marginal spines. Endopodite: 1st joint with 4 spinous ventral bristles and few minute terminal spines at dorsal corner; medial and lateral surfaces of 2nd joint with spines forming clusters; dorsal margin with 3 spinous bristles in 2 groups, proximal with 3 bristles, distal group with 6; ventral margin with 2 groups of spinous bristles, each with 3 bristles; end joint with 3 claws and 4 spinous bristles, all claws with teeth along middle of ventral margin.

Maxilla (Figure 172h): 1st endite with 10 spinous bristles; 2nd endite with about 6 bristles; 3rd endite with about 8 bristles; 1st endite about twice width of 2nd and 3rd; 3rd endite about twice length of 1st and 2nd; coxale with stout plumose bristle; exopodite with 1 short proximal and 2 long terminal bristles. Basale: distal margin with short bristle on anterior corner and long spinous bristle on medial posterior corner. Endopodite: anterior margin of 1st joint with 1 spinous α-bristle, and 5 β-bristles, joint hirsute; end joint obscure but with 4 pectinate clawlike bristles and bare and spinous bristles.

Fifth limb (Figure 172i,j): Epipodial appendage with 55 bristles; 3 endites present. Endopodite: anterior side of 1st joint with 2 bristles near middle of distal margin and 1 short stout spinous bristle with broad base near outer edge; protuberance in front of main tooth bilobate; main tooth consisting of 3 pectinate teeth followed by smooth peg and 1 spinous bristle; large triangular tooth of 2nd joint with 1 large and 1 small node on inner margin; posterior side of joint with usual group of 3 bristles (bristles encrusted on specimen examined), 1 c-bristle, and possibly 1 spinous bristle near outer corner of large tooth (not seen clearly); inner lobe of 3rd joint with 3 spinous bristles, outer lobe with 2; 4th plus 5th joints hirsute with 6 spinous bristles.

Sixth limb: 3 or 4 spinous bristles present in place of epipodial appendage; 1st joint with 3 spinous bristles, 1 long terminal, 2 short medial; 2nd endite with 4 spinous bristles, 3 long terminal, 1 short medial; 3rd endite with 10 spinous bristles, 9 long terminal, 1 short medial; 4th endite with 9 spinous bristles, 8 terminal, 1 medial; end joint with 25 spinous bristles; limb hirsute.

Seventh limb (Figures 172k, 174f, 175a-c): limb with 30 or 31 bristles, 5 in distal group (3 plus 2), 25 or 26 in proximal group, each bristle with 4 to 9 bells, some bristles with a few marginal spines distally; terminal comb with 13 alate teeth; 2 pegs with suaged tips present opposite comb.

Furca (Figures 172l, 175e,f): Each lamella with 10 or 11 claws decreasing in length and stoutness posteriorly along lamella; hairs present medially at base of claws and following last claw.

Eyes and rod-shaped organ (Figures 172b, 174a-d, 176a,b): Lateral eyes small with 2 or 3 ommatidia. Medial eye large, pigmented. Rod-shaped organ elongate, 1-jointed with rounded tip.

Upper lip (Figures 172b, 176): Lip hirsute ventrally with about 4 spines on anterior tip.

Brushlike organ (Figure 172m): Organ consisting of about 6 minute bristles.

Anterior (Figures 172b, 174a-d, 176b): Single large triangular anterior process present above lip.

Parasites: Cuplike stalked protistans abundant on appendages; crinkled filaments and clusters of ovoid protistans also present. Cuplike protistans were also attached to larvae inside the brood chamber of specimen 2 from Residue 192.

Eggs: Specimen from Residue 166, 17 eggs; specimen 1 from station 58, 17 eggs; specimen from station 58 (from collection in South Australian Museum), 12 eggs; USNM 139853, 11 eggs.


Gut content: Juvenile female (USNM 139853) with copepod fragments in its gut; fragments consisting entirely of exoskeletons.

DESCRIPTION OF N-1 ♂.—Carapace size: USNM 141101, length 1.75 mm, height 1.14 mm.

DESCRIPTION OF JUVENILE FROM RESIDUE 192.—Carapace: See Figure 177.

COMPARISONS.—The presence of 2 ventral bristles, 2 dorsal bristles, and 1 or 2 lateral bristles on the 2nd joint of the 1st antenna distinguishes this species from those previously described.

DISTRIBUTION.—This species was collected only in the Kerguelen subregion of Subantarctica at depths of 25 to 55 m (Figure 135).

BENTHIC