28 ORCHESTITD.E. 



Pulex marinus, BASTER, Opusc. Subs. t. 3, f. 7, 8. 



Cancer gammarellus, HERBST. ii. 129, t. 36, f. 2, 3. 



THE eyes are black, irregularly round, moderately 



large, and situated near the top of the head. The 



superior antennae are as short as in Talitrus locusta, 



reaching scarcely to the extremity of the penultimate 



articulation of the peduncle of the inferior pair. The 



inferior pair of antennae in full-grown males are scarcely 



half as long as the animal, they have the first two 



joints fused into the frontal wall of the head ; the last 



joint of the peduncle is longer than the preceding, and 



the articulated extremity is as long as the peduncle. The 



first pair of legs are small, with the penultimate joint 



shorter than the antepenultimate, and the inferior angle 



of each is developed into a scaly protuberance ; the palm 



is short, convex, and edged with a row of single hairs : 



the terminal joint or finger is sharp, scarcely reaching to 



the extremity of the protuberance. The second pair of 



legs have the coxae more largely developed, and almost 



covering those of the first pair : the penultimate joint is 



large and quadrate, being almost as broad as long : the 



palm is convex, and not furnished with any important 



spines or hairs, and armed at the inferior angle with a 



triangular tooth, which corresponds with the extremity 



of the finger. The third pair of legs are shorter than the 



two succeeding, which are subequal. The fourth and 



fifth joints of the last pair are broadly developed in the 



mature males, but in the females and young males they 



are not different from those of the preceding genus. The 



three posterior pairs of appendages are short and spinous, 



the posterior being very short. The middle tail-piece is 



single and pyriform. 



The Shore-hopper is more compressed laterally than the 



