Metavargula calix Kornicker ex Kornicker & Poore 1996

Metavargula calix Kornicker

Metavargula species A, Kornicker, 1994, fig. 110ff.

ETYMOLOGY.—From the Latin calix (cup).

HOLOTYPE.—NMV J37160, adult female on slide and in alcohol.

TYPE LOCALITY.—Slope 32, 38°21.90′S, 149°20.00′E, Victoria, S of Point Hicks; depth 1000 m.

PARATYPES.—None.

DISTRIBUTION.—Slope 32, 1000 m.

DESCRIPTION OF ADULT FEMALE (Figure 10).—Carapace oval with small incisur and upsweeping caudal process (Figure 10a).

Infold: Narrow list with anterior end at about midheight of anteroventral margin continues along ventral infold to point about valve length then broadens to form flange along posteroventral infold and infold of caudal process (Figure 10b–e). Rostral infold with 18 bristles (mostly divided) in row along anterior and ventral margins, 1 long and 2 short divided bristles at midwidth, 1 small bristle proximal to inner end of incisur, and 1 pair of bristles at inner end of incisur. Anteroventral infold with 4 long divided bristles near valve edge (Figure 10b). Anteroventral and ventral infolds with small bristles along list, between list and valve edge, and between list and inner margin of infold. Broad flange of list anterior to caudal process similar to that of M. spadix except pores along posterior edge exit on small processes (Figure 10d,e).

Selvage: Similar to that of M. spadix.

Carapace Size (length, height in mm): NMV J37160 (holotype), 5.12, 3.09; height 60% of length.

First Antenna: Joints 1–6 similar to those of M. spadix. 7th joint: a-bristle almost twice length of bristle of 6th joint, with few spines; b-bristle about longer than a-bristle, with 4 slender filaments, some with spines; c-bristle long with 7 filaments (some with spines) and probably bifurcate tip (tip missing on both limbs of holotype). 8th joint: d-and e-bristles longer than b-bristle, bare with blunt tips; f-bristle shorter than c-bristle, with 9 marginal filaments (some with spines) and bifurcate tip; g-bristle about same length as c-bristle, with 9 marginal filaments (some with spines) and bifurcate tip.

Second Antenna: Protopodite and endopodite similar to those of M. spadix (Figure 10f). Exopodite: Bristle of 2nd joint reaching 9th joint, with 3 or 4 minute proximal hair-like dorsal spines and about 40 ventral spines (proximal 2 or 3 hair-like) (Figure 10g); bristles of joints 3–9 and spines of joints 1–9 similar to those of M. spadix.

Mandible: Coxale, basale, exopodite, and 1st and 3rd endopodial joints similar to those of M. spadix. 2nd and 3rd endopodial joints missing on right limb of holotype. 2nd endopodial joint (left limb of holotype): 3 bristles of ventral margin (1 single, 2 paired) similar to those of M. spadix; dorsal margin with 21 bristles (5 long spinous bristles, 3 medium length, and 13 short spinous medial).

Maxilla (Figure 10h,i): Protopodite with plumose dorsal bristle. Endite I with 11 spinous bristles; endite II obscured; endite III obscured, but with 1 proximal and about 5 distal bristles. Basale with ventral bristle reaching past distal end of 1st endopodial joint. Exopodite and 1st endopodial joint similar to those of M. spadix except inner beta-bristle bare. 2nd endopodial joint similar to that of M. spadix except smallest c-bristle with few spines.

Fifth Limb: Epipodial appendage with 62 plumose bristles. Protopodial tooth and 1st and 2nd exopodial joints similar to those of M. spadix, except proximal triangular tooth of main tooth without spines. 3rd exopodial joint similar to that of M. spadix except outer unringed bristle of inner lobe with few spines, and both bristles of outer lobe of both limbs with long proximal hairs. 4th exopodial joint with 4 bristles (bare or with short spines). 5th exopodial joint fused to 4th, with 2 bristles (bare or with short spines); very small spinous process at corner near 4th joint.

Sixth Limb (Figure 10j): With 6 bare epipodial bristles; small sclerotized boss on posterior edge lateral to proximal bristle. Endite I with 2 or 3 medial bristles and 1 long terminal bristle; endite II with 4 medial bristles and 2 long terminal bristles; endites III and IV each with 3 terminal bristles (middle bristle shorter). End joint with 15 bristles with long proximal and short distal spines (2 near anterior smaller), then space and 3 bristles (anterior with long proximal and short distal spines, others plumose). Limb hirsute. (Not all bristles shown.)

Seventh Limb: Holotype: One limb with 33 bristles (terminal group with 10 bristles on comb side and 9 on peg side; proximal group with 6 bristles on comb side and 8 on peg side); other limb with 36 bristles (terminal group with 10 bristles on comb side and 11 on peg side; proximal group with 6 bristles on comb side and 9 on peg side). Each bristle with up to 7 bells. Comb with 16 slender ringed spinous teeth with recurved slightly bulbous tips. Single ringed spinous peg with slightly bulbous tip opposite comb (Figure 10k). Spines of comb teeth and peg visible only at high magnification (×100 objective, ×15 ocular).

Furca: Similar to that of M. spadix.

Bellonci Organ (Figure 10l): Cylindrical with small process at tip.

Eyes: Medial eye well developed, light amber color (Figure 10l). Lateral eye small with 5 or 6 minute cells and reddish brown pigment (Figure 10m); eye generally visible through shell.

Upper Lip (Figure 10n): Similar to that of M. spadix.

Genitalia: Oval on each side of body anterior to base of furca.

Anterior of Body (Figure 10l): With small rounded anterior process.

Posterior of Body: Evenly rounded, bare.

Y-Sclerite: Typical for family, with 1 ventral and 1 dorsal branch.

COMPARISONS.—The carapace of M. calix differs from that of M. spadix in being larger (length 5.12 mm compared to 3.73 mm) and in having stouter processes along the posterior edge of the flange of the broad list anterior to the caudal process; the appendages differ in having 6 rather than 3 epipodial bristles on the 6th limb and 15 rather than 6–9 teeth in the comb of the 7th limb. Metavargula calix differs from M. adinothrix Kornicker, 1975:131, in having 2 rather than 3 cusps on the cutting tooth of the maxilla, 5 rather than 6 pectinate teeth on the main tooth of the 5th limb, 6 rather than 10 epipodial bristles on the 6th limb, and 33–36 rather than 51 bristles on the 7th limb.