Some Bathyal Pacific Amphipoda Collected by the TJ.S.S* Albatross 
J. Laurens Barnard 1 
Several bathyal Amphipoda from the U.S.S. 
"Albatross” expeditions of 1838 onward 
(Holmes, 1908; Shoemaker, 1925) remained to 
be determined in the collections of the U.S. 
National Museum, and the results of their study 
are presented here. Increasing interest is being 
shown in faunas on bottoms of 200-2000 m. 
Although these depths comprise only 8.5% of 
the world’s sea-floor, they perhaps support the 
remnants of the ancient abyssal fauna occupying 
depths greater than 2000 m prior to the Tertiary 
cooling of the seas (Madsen, 1961; Barnard, 
1961, 1962; and their bibliographies ) . 
Bathyal benthic depths outside of the Nor- 
wegian polar basin have not been well explored 
for amphipods, so that any records are of great 
interest. These early Albatross collections, al- 
though small and widely scattered, contain very 
well-preserved and intact specimens of seven 
previously known and six new species. 
Of especial interest is another record of Meso- 
pleustes abyssorum Stebbing and the oppor- 
tunity to discuss its relationship among three 
families that it intergrades. The question of 
speciation in the genus Eusirella is reopened. 
No depth is known for a new species of Melita, 
but its poorly pigmented eyes may indicate a 
deepwater origin. 
Not all of the species recorded here are ben- 
thic, the members of the genera Rhachtropis , 
Koroga , Eusirella , Cyclocaris, and Parandania 
being bathypelagic or demersal. 
family LY SI ANASSIDAE 
GENUS Aristias Boeck 
Aristias adrogans, new species 
Fig. 1 
DIAGNOSIS: Eyes very pale, scarcely evident, 
no organized ommatidea apparent, composed 
1 Beaudette Foundation, Santa Ynez, California. 
Manuscript received March 14, 1963. 
simply of dense tissue; antennal flagella 10- 
articulate; epistome and upper lip fused but 
bounded by a hollow incision, neither produced 
beyond the other; first coxa broader than long, 
fifth and sixth with long, broad posterior proc- 
esses; palm of gnathopod 2 formed of a broad 
projecting thumb; all pereopods with a small 
conical distal process on article 6; article 4 of 
pereopod 3 overlapping article 5 halfway or 
less, article 5 half or less as long as article 4 
and becoming shorter with each pereopod; sec- 
ond pleonal epimeron tending to project at 
lower corner; first urosomal segment lacking a 
dorsal process; uropods 1 and 2 multispinose; 
inner ramus of uropod 3 not quite reaching end 
of article 1 of outer ramus; lobes of telson 
relatively narrow, each armed apically with a 
single spine. 
HOLOTYPE: USNM no. 108629, male, 15 mm. 
TYPE LOCALITY: Albatross Station 4781, the 
Near Islands, Alaska, 52° 14' 30" N, 174° 13' 
E, 482 fms, June 7, 1906. 
MATERIAL: Two specimens from the type 
locality. 
RELATIONSHIP: Three species have been de- 
scribed lacking eyes according to Gurjanova’s 
key (1962). These are A. topsenti Chevreux 
(1900), A . microps Sars (1895), and A. fal- 
catus Stephensen (1923). The present species 
is so closely related to A. falcatus that one would 
consider them to be the same species, were not 
the trend in lysianassid systematics, especially 
as practiced by Gurjanova (1962), to seek ex- 
tremely minute specific differences. Such has 
also been practiced in the genus Orchomene 
( = Orchomenella and Orchomenopsis) . Because 
Stephensen makes a point of using the condition 
of the palm of gnathopod 2 as a character of 
distinction between A. commensalis and A. fal- 
catus , it may also be used in the present species, 
which has a distinctly produced palm and so 
differs from A. falcatus but is similar to A. 
topsenti. Aristias microps has this palm very 
narrowly acute. In A. falcatus the inner ramus 
of the third uropod exceeds article 1 of the 
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