Bathyal Amphipoda — Barnard 
329 
DISTRIBUTION: Boreal species: North Atlantic 
at Norway, Kattegat, Holland, France as far 
south as Boulonge, British Isles, New England 
as far south as Connecticut; Arctic at Bering, 
Chukchi, and East Siberian seas; North Pacific 
at Kodiak Island, Alaska. Depth range 40- 
150 m. 
family ISCHYROCERIDAE 
genus Ischyrocerus Kroyer 
Ischyrocerus h or tat or, new species 
Fig. 10 
DIAGNOSIS: Eyes obsolete, forming a barely 
perceptible white mass composed of finely par- 
ticulate 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, pereo- 
pod 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 pos- 
teroventrol 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 /. 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 Gurja- 
nova (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 Gurja- 
nova (1951). 
The epistome is similar to that drawn herein 
for I. malacus, n. sp. 
DISTRIBUTION: The type locality and off Ar- 
chipielego de los Chonos, Chile, 45° 35' 00" 
S, 75° 55' 00" W, 1050 fms, Feb. 11, 1888. 
Ischyocerus malacus, new species 
Fig. 11 
DIAGNOSIS: Eyes obsolete, pigmentless in al- 
cohol but bearing tiny distinct ommatidea mod- 
erately scattered; antennae about equal in length, 
flagellum of antenna 2 not longer than article 5 
of peduncle; coxa 5 three-fourths as long as 
coxa 4; pereopod 5 with lower posterior corner 
of article 2 subacutely produced, the corners of 
pereopods 3 and 4 bluntly produced; uropod 3 
slender, elongated, rami half as long as peduncle, 
apex of outer ramus ornamented (see figures), 
inner ramus with a single apical spinule; telson 
linguiform, apically rounded, armed with two 
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. 108636, female, 9.0 
mm. Unique. 
TYPE LOCALITY: Albatross Station 4538, 
Monterey Bay, California, 6.5 miles S, 85° E 
of Pt. Pinos Lighthouse, 871 fms, May 31, 1904. 
RELATIONSHIP: This species resembles 1. 
h or tat or, n. sp., in its general appearance but 
from the diagnoses one may see innumerable 
small differences. The eyes of 1. malacus are 
slightly better composed, coxa 5 is longer, the 
rami of uropod 3 are longer, and the antennae 
are equal in length. 
The produced lower corner of article 2 on 
pereopod 5 removes this species from these 
relatives: I. megacheir (Boeck), I. hanseni 
