STALK-EYED CRUSTACEA 113 



another ridge, not so prominent, starting from the angle 

 formed by the preceding, edges the gastric region and 

 is prolonged above the orbit. The urocardiac lobe is 

 prominent, and has some granulations. The general 

 surface is smooth. The front is triangular and slightly 

 advanced. The antero-lateral edges are laminiform and 

 almost straight ; magnified, they appear finely ridged. 

 The postero-lateral border has a prominent point situated 

 at the origin of the branchial ridge ; the portion of this 

 border between this projection and the lateral angle is 

 straight. The posterior edge forms with the preceding 

 a very indistinct angle. The external maxillipedes and 

 the sternum are granular. The pincers are of unequal 

 size, short, and have on their edges finely cut crests. The 

 faces are smooth. The hand is swollen, and the movable 

 finger is robust and bowed. The fourth joint of the 

 walking legs is hidden under the lateral expansion of 

 the carapace. 



Range. — St. Thomas, Charlestown. 



Tribe II. Cyclometopa. 



Cyclouietopa . . . Miers, White. 



Cyclometopes , . . H. Milne Edwards. 



Arcuata Latreille. 



Cancroidea .... De Haan, 



The carapace is very large and bowed in front, con- 

 tracted posteriorly, being generally broader than long ; 

 sometimes it is circular. The hepatic regions are well 

 developed, and occupy the most of the lateral portion 

 of the test. The front is transverse and slightly or not 

 turned down. The orbits are directed upwards and 

 forv/ards. The eyes are always perfectly mobile, and 

 8 



