504 CHELURTD.E. 



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 antennae 

 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 antennae 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. 



