STALK-EYED CRUSTACEA 53 



c. The horns of the rostrum diverging throughout their 

 course; soldered together to half their length at their 

 base. — [P. erinacea?) 



1. Pisa antilocapra. 



Pisa antilocapra . Stimpson, A. Milne Edwards. 



Carapace subovate, rather narrow, pubescent, and 

 spinous, with a strong acute spine on the hepatic region ; 

 seven to ten smaller spines on the branchial regions, and 

 four, forming a rhomb, on the intestinal region. There 

 are some sharp tubercles on the cardiac and gastric 

 regions. Rostrum horizontal, equalling in length more 

 than a third of the length of the postfrontal portion of 

 the carapace; horns diverging in the basal third, rather 

 slender, acute and straight, or slightly curved inwards 

 near their extremities. Przeocular spine slender, less than 

 a third as long as the rostrum. On the superior margin 

 of the orbit there are two spiniform teeth between the 

 base of the przeocular spine and the external angle, which 

 is also acute. Spine of basal joint of external antennae 

 much smaller than the prsocular spine. 



Legs pubescent, with their fourth joint spinous above. 

 Last joint of walking legs unarmed on their inferior edge. 



Range. — West Indian Sea. 



2. Pisa praelonga. 



Pisa pnelonga . Stimpson, A. Milne Edwards. 



Carapace long and narrow, the width across the 

 branchial regions being very little greater than that 

 between the orbits ; sparsely hairy, and has a few small 

 spines on the sides. Surface under the hairs smooth. 

 Rostrum large, as long as one-third the length of the 



