CALLISOMA CRENATA. 121 



white ground. The superior antennse are very stout at 

 the base ; the first joint of the peduncle is nearly as long 

 as the head, and almost as thick as long; the second 

 joint is very short, and a little narrower than the first; 

 the third is very short, and almost covered by the pre- 

 ceding; the flagellum has the first articulus very long, 

 and broader at the base than at the distal extremity, the 

 remaining articuli (six or seven in number) are small. 

 The inferior antennaj are slender, and about one-third 

 the length of the animal ; the peduncle is rather longer 

 than the peduncle of the superior ; the flagellum is very 

 slender, and lies folded beneath the body of the animal. 

 The first pair of arms are long and slender, and have 

 the hand long and narrow, the margins parallel, the 

 distal extremity being anteriorly armed with several 

 fasciculi of strongly curved hairs ; the finger consists 

 of a thick brush of short stiff hairs. The second pair 

 are more robust than the first ; the hand is ovate, 

 with the inferior angle produced and depressed; it ter- 

 minates in a small tooth ; the finger is rather longer 

 than the process of the hand, and has the inner margin 

 waved ; together they form a very perfect claw, which 

 bears a strong resemblance to those existing in some 

 species of Soldier Crabs {Pagurus Dillwynii.) The third 

 and fourth pairs of legs are not very robust ; the three 

 last gradually increase in length. The first squamose 

 plate of the fifth pair of legs is almost round, and cor- 

 responds anteriorly with a deep excavation in the pre- 

 ceding ; the second squamose joint is produced pos- 

 teriorly, and is broader than long ; the next joint is 

 very short ; but the fourth is produced posteriorly into a 

 small squamose plate, fringed with hairs ; the wrist is 

 short, and stouter than the hand, which is long, slender, 

 and has the margins parallel. The two posterior pairs 



