504 
CHELTJRIDiE. 
The male animal in this species is a little larger than 
the female, and can readily be recognized by the greater 
length of the dorsal tooth, and that of the posterior pair 
of caudal appendages. 
The third segment of the tail is armed with a large 
curved dorsal tooth, situated upon the posterior margin. 
The eyes are small and round. The superior antennas 
are not longer than the peduncle of the inferior ; the 
joints of the peduncle are subequal in length ; and the 
flagellum, which consists of six articuli, is not quite 
so long as the peduncle ; the secondary appendage is 
biarticulate * and slender. The inferior antennas are 
about half the length of the body of the animal ; the 
joints of the peduncle gradually increase in length and 
breadth, and are furnished with long hairs ; the flagellum 
is of a long elliptic form, laterally compressed, and thickly 
fringed with long hairs in the male : it is smaller and rather 
more oval in the female. The first pair of legs have the 
hand scarcely dilated, the margins being nearly parallel, 
the palm straight, and little longer than the diameter of 
the hand, caused by the inferior angle being slightly pro- 
duced inferiorly. The finger is short, sharp-pointed, and 
slightly curved, forming, with the hand, a tolerably per- 
fect chelate organ. The second pair of legs have the 
hand somewhat longer, and still less dilated than that of 
the first, with the inferior angle of the palm anteriorly 
produced to a point, which, with the short and curved 
finger, forms a perfectly chelate hand. All the walking 
legs are short, and none have the thighs dilated : the 
last three have the hands strongly spinous upon their 
anterior margins. The natatory appendages are short ; 
the multi-articulate flexible branches are fixed upon a 
* Professor Allman figures it as four-jointed, the three terminal joints 
being very minute ; it probably varies with age. 
