ASELLUS, 341 
ISOPODA. ASELLID. 
NORMALIA. 
Genus—ASELLUS. (Geoffray.) 
Generic character. Flagella of all the antenne multiarti- 
culate, lower pair more than half the length of the body; eyes 
round and lateral; pereiopoda uniunguiculate ; pleon with two 
long and exserted bifid appendages. 
THE species of this genus have the body oblong, rather 
narrowed towards the head, with eight rather deep lateral 
incisions between the various segments of the body, 
which are depressed and slightly irregular on the upper 
surface, the sides being furnished with strong, irregular 
lengthened spines. The head is transverse, scarcely nar- 
rower than the body, the fore margin nearly straight, the 
eyes small, round, and quite lateral. ‘The upper antenne 
about twice the length of the head, and very slender; 
the lower antennz more than half the length of the 
animal, cylindrical, all the antenne having a multiarti- 
culate flagellum, which is very long in the lower pair. 
The segments of the body are nearly of equal size, each 
being marked with an impressed transverse line near the 
base. The fore pair of legs are rather short, robust 
(especially in the males), and terminated by a subcheli- 
ferous hand, with apical hook-like finger; the three fol- 
lowing pairs of legs are longer, much more slender, and 
simply ambulatory; and the three hind pairs of legs are 
gradually longer, all being terminated by a simple acute 
and curved finger. The tail consists of a large shield- 
like joint, with indications of two very short joints at 
