MUSEUM OF COMPARATIVE ZOLOGY. V7t 
merus and carpus of the chelipeds and all the segments of the ambulatory legs 
from the ischium to the dactylus inclusive are banded transversely with bright 
red on a yellowish ground. 
Catapagurus diomedes, sp. nov. 
The carapace is smooth and naked, and divided into an anterior and pos- 
terior section by the cervical groove. The anterior margin projects slightly 
between the eyestalks, forming a blunt rudimentary rostrum. The gastric 
region is sharply defined, and presents an indistinct longitudinal furrow on 
each side of the median line; it is lightly convex in both directions. The 
branchial regions of the right and left sides are strongly inflated and sharply 
separated from each other by a re-entrant angle formed by the curving for- 
ward of the posterior border of the carapace on each side of the median line. 
The eyestalks are rather long and slender, being about equal in length to 
the anterior section of the carapace. The ophthalmic scales are very small and 
minutely bifid at the tip. The third segment of the antennulary peduncle is 
about two thirds the length of the eyestalk, and increases in diameter from the 
base to the distal end; the superior flagellum is rather longer than the distal 
segment of the peduncle, and its enlarged ciliated basal portion forms rather 
more than one third of its whole length. The inferior flagellum is about one 
half as long as the superior, and is composed of about eleven segments. The 
peduncle of the antenna surpasses the eyestalk by one half the length of its 
distal segment ; the acicle is long and slender, tipped with a few sete ; it 
reaches forward a little beyond the eye; the flagellum reaches beyond the tips 
of the ambulatory legs. The chelipeds are nearly alike in shape and size ; 
their segments are clothed with long sete, which assume a tomentose appear- 
ance on the chele; the carpus is about equal in length to the chela, its inner 
face is perpendicular, the inner margin of the upper side is armed with seven 
small spines; there is also a spine at the distal end of the superior margin of 
the carpus ; the chela is short and thick, the fingers about the same length as 
the basal portion of the propodus, slightly down-curved, meeting throughout 
their length, working horizontally. The ambulatory legs are of nearly equal 
length, surpassing the chelipeds, setose, the carpus armed with a sharp tooth at 
the distal end of its upper side ; the propodus is twice as long as the carpus, 
the dactylus is considerably longer than the propodus, and, like that segment, 
is distinctly curved ; it is tipped by a small horny nail. The fourth pair of 
legs is but slightly subcheliform ; the rasp is formed of a single row of scales. 
There are three small rudimentary appendages on the left side of the abdo- 
men ; the first and second of these are two-branched, the secondary branch 
being exceedingly minute. 
The sexual tube, which issues from the coxal segment of the last thoracic 
appendage of the right side, is very long in this species. 
Length of carapace, 5.5 mm. ; abdomen, 8 mm.; cheliped, 12.5 mm.; last 
ambulatory leg, 17.5 mm. ; ocular peduncle, 2.6 mm, 
