“Ischyrocerus hortator, new species
Diagnosis: Eyes obsolete, forming a barely perceptible white mass composed of finely particulate tissue; antenna 1 shorter than antenna 2; flagellum of antenna 2 not longer than article 5 of peduncle; .coxa 5 half as long as coxa 4; pereopods 4 and 5 with lower posterior corners of second articles subconically produced, pereopod 3 less produced; uropod 3 very slender, elongated, rami about 37% as long as peduncle, apex of outer ramus ornamented (see figures), inner ramus with a single apicle spinule; telson linguiform, apically rounded, armed with two lateral spines; gnathopod 2 with long palm, scarcely distinct from but longer than hind margin of article 6, near finger hinge bearing a poorly bifurcate process.
Holotype: USNM no. 108634, female, 13.8 mm, ovigerous.
Type locality: Albatross Station 2789, off Isla de Chiloe, Chile, 42° 36' 00" S, 75° 28' 00" W, 1342 fms, Feb. 12, 1888.
Material: Albatross 2788 (specimen 9.0 mm); Albatross 2789 (holotype, and a 9.5-mm specimen).
Relationship: In the obsolescent eyes and the short rami of uropod 3 this species resembles I. tenuicornis (Sars 1885) and I. brevicornis (Sars 1885), but differs by the produced posteroventrol corners of the second articles of pereopods 4 and 5 and the distal palmar process of gnathopod 2. It has different proportions of the antennae than I. tenuicornis, and different proportions of the peduncle and rami of uropod 3 than does I. brevicornis.
The new species differs from I. commensalis Chevreux (1900) by the shorter fifth coxa, the obsolescent eyes, and shorter rami of uropod 3, but in other respects the two species are similar.
This species is related to I. chamissoi Gurjanova (1951), but differs by the produced lower corners of the second articles on pereopods 3-5. The shorter rami of uropod 3 distinguish the species from I. krascheninnikovi Gurjanova (1951), according to her key and description. The new species lacks the distal peduncular seta on uropod 3 shown for I. rhodomelae by Gurjanova (1951).
The epistome is similar to that drawn herein for I. malacus, n. sp.
Distribution: The type locality and off Archipielego de los Chonos, Chile, 45° 35' 00" S, 75° 55' 00" W, 1050 fms, Feb. 11, 1888.”
(Barnard, 1964: 329)
