334 ASELLIDA. 
of the cephalon considerably within the margin. The 
anterior pair we take to be those that are figured pos- 
teriorly in our cut, the basal parts of which are seen 
through the transparent tissue. These have the joints 
of the peduncle, which we believe to be of the normal 
number, surmounted by a slender flagellum consisting of 
four articuli. The posterior pair of antennz are much 
longer, having the joints of the peduncle very long, and 
terminate in a slender flagellum, consisting of one long 
and four short articuli. 
The anterior pair of legs (first pair of gnathopoda) are 
moderately robust, and terminate in a hand of con- 
siderable prehensile power. All the other legs are 
slender and tolerably free from hairs. The pleon is pear- 
shaped, broader anteriorly: on each side, somewhere 
about two-thirds from the anterior margin, the posterior 
pair of pleopoda are implanted in the margin, these are 
fringed with two or three very fine cilia; between this 
and the anterior margin the edge of the pleon is fringed 
with a delicate, serrated margin: so transparent is the 
structure, that it escaped our observation, when we drew 
the figure, that nine minute teeth were present. On 
each side of the pereion the hairs are connected 
together by an exquisitely fine fibrous membrane, that 
nearly reaches to their extremities. 
The animal lives in the mud; two or three specimens 
have been taken by Mr. Robertson at Cumbrae, to whom 
we are indebted for it. 
