GAMMARELLA BREV1CAUDATA. 
331 
suddenly to decrease in size. The eyes are smali and 
round. The superior antennae are about half the length 
of the animal ; the flagellum is about the same length as 
the peduncle ; the secondary appendage consists of four 
articuli. The inferior antennae scarcely reach beyond 
the extremity of the peduncle of the superior ; the 
flagellum is not longer than the last joint of the ped- 
uncle. The first pair of legs are very small and slender. 
The second, as if to compensate for the insignificant 
character of the first, are extremely large, the hand 
being nearly equal in length to the head and first three 
segments of the body, it is of a long oval form, slightly 
tapering to the distal extremity ; the palm occupies the 
whole length of the inferior margin : the finger is very 
long and robust, and the wrist is extremely short. The 
last three pairs of legs have the thighs dilated into 
broadly oval plates ; and the fingers are short and strong, 
and articulated, with the hands at the anterior margin of 
the distal extremity. The caudal appendages are short, 
the branches being shorter than the peduncles, the last 
being single branched, a strong spine being probably the 
rudiments of the obsolete second branch. The central 
tail-piece is broad, divided nearly to the base, having 
each division subapically crowned with a short spine. 
The animal is of a dark olive-green colour. Under 
the microscope the surface is seen to be covered with 
stiff hairlike processes and spots ; these last being the 
result of small groups of little spinules. 
We have but little hesitation in referring Gammarus 
punctimanus of Costa to this species, although that author 
represents the upper antennae as destitute of a supple- 
mental appendage. 
The animal was first taken at Morbihan, on the coast 
of France, by M. Milne Edwards. It has since been 
