350 ASELLIDA. 
maxille are also very delicate, furnished with three 
oblong-ovate terminal plates, setose at their extremities. 
The legs are short and slender, all being formed nearly 
alike, the four anterior ones being, however, rather more 
robust and tuberculated on the basal joints, all terminat- 
ing with a small slender curved finger. The tail consists 
of six segments, of which the four basal ones are short 
and equal, with the posterior margin entire; the fifth has 
the posterior margin irregular, and the sixth is large, 
semicircular, flattened, with a slight central ridge; on each 
side it bears a lateral appendage, of which the basal 
portion is nearly square, with the outer margin notched, 
and terminating in a strong, curved, movable spine; the 
apical portion forms a slender style, with strong bristles at 
its extremity, which appears to be separated into a minute 
articulation. ‘The ovigerous pouch of the female consists 
of four pairs of scales, affixed to the middle segments 
of the body, and the tail is furnished on its underside 
with six pairs of scale-like, branchial plates, forming three 
rows, which are naked and of equal size. These plates 
are received, as in the Spheromide, in a cavity formed by 
the excavation of the underside of the caudal segments. 
In this respect, and especially in the segmentation of the 
pleon, the genus is removed from the remainder of the 
Asellide; indeed, Dr. Leach formed it into a distinct race 
in his great family Cymothoade, which also included the 
Serolide, Higide, and Spheromide. 
The whole of the dorsal surface is covered with stiff, 
pinnated hairs, amongst which numerous minute para- 
sites, somewhat like Hchinorhynchi and Acari, are con- 
stantly to be seen.. They even infest the branchie. 
