“Ammothea calmani n. sp. (Figs. 54 and 55).
A. striata?, Calman, 1915, p.55
St. 181. 12. ii. 27. Schollaert Channel, Palmer Archipelago, 64°20’S, 63°01’W, 160-335m.; m. St. Large otter trawl: 1 immature specimen with large chelophores.
This immature specimen belongs to the same species as the large male referred, with considerable doubt, to A. striata by Calman (1915, p. 55). The adult specimen may be regarded as the holotype.
Description of immature specimen. Trunk with second to fourth lateral processes separated by their own diameter. Transverse body ridges prominent but not greatly elevated in the middle line. Cephalic segment equal to the sum of the two succeeding segments. Ocular tubercle a little higher than wide, apex bluntly pointed and on a level with the median transverse ridge. Anterior very much larger than the posterior pair of eyes (Fig. 54).
Proboscis short, sub-cylindrical; length almost three times the width and approximately equal to the sum of the two anterior segments of trunk.
Abdomen elevated at an angel of about 45°, reaching a little beyond fourth lateral process.
Chelophore slightly longer than proboscis; scape longer than chela and rather slender (length 2.5 times the distal width).
Palp considerably longer than proboscis, with nine segments, of which the second and fourth are subequal (Fig. 55a).
Oviger small but with all ten segments distinct.
Third leg rather slender; femur 5.5 times as long as wide; second tibia the longest segment. Propodus with two large and one small spine on the proximal ventral margin (Fig. 55d); the terminal segments are very similar in all four legs.
Measurements (mm).
Length of proboscis
5.8
Width of proboscis
2.2
Length of trunk
10.5
Length of cephalic segment
4.2
Width of anterior border of cephalon
3.1
Width across second lateral processes
7.9
Length of abdomen
3.6
Length of scape
4.0
Length of chela
3.0
Third leg:
First coxa
1.8
Second coxa
4.0
Third coxa
1.8
Femur
11.0
First tibia
10.7
Second tibia
12.0
Tarsus and propodus
5.0
Claw
2.4
Auxiliaries
0.8
Remarks. The adult male is not in a sufficiently good condition to give accurate measurements. It agrees with the immature specimen in most respects. The transverse body ridges on the second and third segments are more massive and are higher than the ocular tubercle. The chela is greatly reduced so that the chelophore is shorter than the proboscis. A fourth spine is present on the propodus of each walking leg (Fig. 55c) and the setules are arranged in distinct longitudinal bands on the three long segments. Segments 2-6 of the oviger measure 4.4, 3.6, 4.0, 4.4, 2.5 mm. respectively; the terminal segments are represented in Fig. 55b. The right palp is slightly abnormal near the tip; segments 7 and 8 seem to be fused together.
This species appears to be related to A. stylirostris, from which it can easily be distinguished by (1) the shape of the proboscis, (2) the longer claw and much larger spines on the propodus, (3) the larger chelophore, and (4) the much shorter fourth palpal segment.
Distribution. Palmer Archipelago and off Oates Land.” (Gordon 1932, p.104-106)
