2 W. T. CALMAN. 
in one case a very little behind the orbital notch, and the last two are close to the 
apex of the rostrum; lower margin with six to nine teeth (usually seven.) No 
supra-orbital teeth, antennal tooth distinct from the lower orbital angle, antero- 
lateral corner of carapace with a minute (pterygostomial) tooth. 
Third abdominal somite with dorsal surface strongly elevated or ‘‘ humped,” 
but without a definite tubercle as in Chorismus tuberculatus. Sixth abdominal 
somite without movable lateral spines. 
Peduncle of antennules reaching to or nearly to two-thirds the length of 
rostrum, third segment one-half the length of second, spine of first segment 
(‘“‘stylocerite”) narrow and acute, reaching to middle or quite to end of second 
segment; flagella subequal, or inner slightly longer than outer, extending beyond 
tip of rostrum by one-third to nearly half their length. Antennal scale broad, about 
equal in length to rostrum, outer edge distinctly and evenly convex, apex broadly 
rounded, outer spine short. 
Mandible with small incisor process and palp of three segments, the first broader 
than, and as long as the second. Third maxilliped extending nearly to tip of 
antennal scale, terminal segment twice the length of preceding. Exopod well 
developed. 
First leg extending beyond penultimate segment of third maxilliped, carpus 
slightly excavate distally, about equal in length to the hand. Second leg extending 
beyond tip of antennal scale, carpus of eleven, merus of three, and ischium of two 
segments. Remaining legs moderately stout, fifth leg extending forwards nearly 
to tip of antennal scale. 
Telson not greatly narrowed distally, tip rounded, with seven spines. Inner 
plate of uropods subequal to the telson and very little shorter than the outer plate, 
which is broadly rounded at the tip. 
The branchial system comprises five pleurobranchie on each side on the last 
five thoracic somites, an arthrobranchia on the third, and a podobranchia on the 
second maxilliped. There are epipods on the third maxillipeds and on the first two 
pairs of legs. 
Young males (55-59 mm. in length) and females (42 mm.) Body a little more 
slender and the rostrum relatively longer, distinctly exceeding the length from orbit 
to back of carapace. Flagella of antennule little longer than rostrum. Outer edge 
of antennal scale straight. In two specimens (6 and ?) there are twelve segments 
in carpus of second leg. 
The co-typical specimen of Hippolyte antaretica used for comparison is an 
ovigerous female, about 60 mm. in total length. It agrees perfectly with the 
‘Discovery’ specimens except in the following points :—Of the seven teeth on the 
upper edge of the rostrum only one is close to the point, not two, as in our 
specimens ; the antennal scale is slightly longer than the rostrum, and its outer edge 
(as in our specimens of similar size) is nearly straight; the third maxillipeds are a 
