Bathyal Amphipoda— BARNARD 
323 
having article 5 of pereopod 1 much shorter 
than article 4. 
The calceoli are present only on the medial 
faces of the articles of the antennae although in 
the figure of the animal drawn here they are 
shown rather strongly because they appear under 
low-powered microscopy to show through the 
very transparent appendages. 
Birstein and Vinogradov (I960) removed 
Shoemaker’s (1945) identification of E. elegans 
Chevreux to E. multicalceola, but I believe this 
move is premature, for Shoemaker’s specimen 
has several good characters worthy of at least 
subspecific value if not more so. Especially im- 
portant is coxa 1 projecting forward strongly in 
Shoemaker’s specimen; the fifth articles of the 
gnathopods are of similar length in both pairs 
and relatively shorter than in E. multicalceola; 
the dactyli of the gnathopods extend nearly the 
full length of article 6, and hence the palm is 
longer and more distinctly defined by spines 
than in E. multicalceola; the accessory flagellum 
is of cylindrical, not bractiformal shape as seen 
on my specimen. There may be differences in 
the mandibular palp not mentioned by Shoe- 
maker. Shoemaker believed that E. multicalceola 
as well as E. valdiviae Schellenberg (1926) were 
synonymous with E. elegans Chevreux. Since 
Thorsteinson had a male, and Birstein and Vino- 
gradov and I figure females, we show that there 
are no sexual differences in E. multicalceola. 
Eusirella valdiviae was not well figured and 
the gnathopods, although slender as in E. multi- 
calceola and Shoemaker’s specimen, may be 
turned and may not have been drawn flat; even 
so they have short dactyls as in E. multicalceola. 
The truncate first coxae also show that E. valdi- 
viae is closely related and possibly the senior 
synonym of E. multicalceola. 
Stephensen’s (1944) figures of E. elegans 
show coxa 1 acutely pointed forward and show 
sexual differences only in antennae. 
Because of zoogeographical considerations 
these species should not be fused until more 
material from the South Atlantic area can be 
examined in greater detail. Eusirella multical- 
ceola is a North Pacific species, E. valdiviae is 
known from the South Atlantic, and E. elegans 
and Shoemaker’s specimen are from the middle 
North Atlantic. Shoemaker’s specimen is most 
closely related to E. elegans because of the first 
coxa. Hence E. elegans might be an endemic 
Fig. 5. Mesopleustes abyssorum (Stebbing). Female, 22.0 mm, Albatross 5082: a, head; b, outline of maxilla 
2; c, d, dorsal and lateral views of telson; e, pleonal segments 1-3, left to right; f, enlargement of a pereonal 
segment above the coxa to show sculpture; g, enlargement of dorsal edge of a pleonal segment to show sculp- 
ture; h-j, distal ends of coxae 1-3. Cyclocaris guilelmi Chevreux. Male, 6.3 mm: k, coxa and articles 2 and 3 
of gnathopod 1. 
