442 STALK-EYED CRUSTACEA 



the frontal border carries in front a single small spine. 

 The orbital notch is straight and deep ; its external 

 borders is very broad and has fine spines. The median 

 keel is very elevated, and there is another keel on each 

 side. The posterior border of the carapace is notched 

 and has some spines. 



The basal joint of the internal antennae is very pointed, 

 but it is slightly dilated inside, so the borders are not in 

 contact in the middle line ; there is a wide space in 

 front of the rostrum. 



The abdomen is very rough, and the second, third, 

 fourth, and fifth segments have above a projecting keel 

 terminating in front in a strong recurved spine. 



There is no difference between male and female. 



Range. — Barbados, Grenada, Grenadines, St. Lucia, 

 Nevis. 



2. Pentacheles spinosus. 



PentacJieles spinosjis . . A. Milne Edwards. 

 PolycJieles J idler i . . . Spence Bate. 



The carapace is smooth and wide in front. There are 

 two sharp points forming the rostrum. The orbital notch 

 is very wide and the eye is large ; the borders of this 

 notch are unarmed. 



The lateral borders of the carapace have strong spines. 

 The median keel, instead of being granular, has spines 

 arranged singly or in pairs; three pairs on the cardiac 

 region, one pair in the middle of the gastric region, while 

 in front and behind this region there is but one spine. 

 The branchial keels have about five spines. There is a 

 wide space in front of the rostrum at the base of the 

 internal antennae, of which the basal articulation is 

 slightly enlarged and is not in contact in its whole 

 extent with the one on the opposite side. 



