STALK-EYED CRUSTACEA 453 



The internal antennae have on the outside a spine, and 

 on the inside an appendage which is rudimentary and 

 terminates in two subequally short flagella. The external 

 antennae have a basal scale, broad at the base, narrow at 

 the apex, strong and rigid on the outside, and terminates 

 in a strong sharp tooth. The flagella are moderately 

 long. 



The abdominal appendages are one-branched and 

 very short ; the first and second pair, in the male, have 

 membranous appendages. 



The gills are attached to the body wall, except the 

 last segment, to the membrane between the first joint of 

 the two maxillipedes, and all the legs except the last pair, 

 and the body of the animal. There is a branchial lash 

 attached to all these limbs, except the two posterior pairs 

 of legs. 



Range. — West Indies, South America, Cape Verde 

 Islands, Mediterranean Sea, China, Japan, Indian Ocean, 

 New Guinea. 



I. Sicyonia carinata. 



Sicyonia carinata . . Olivier, Milne Edwards. Dana, 



Spence Bate, 

 Pal(Binon carinatus . . Olivier. 



The dorsal surface is carinated in the median line 

 from the rostrum to the posterior segment of the abdomen. 

 The rostrum, directed obliquely upwards, is armed with 

 two small teeth, with indications of a third at the extremity, 

 and with two larger teeth posterior to the gastric region ; 

 a short tooth on the anterior margin of the carapace, 

 corresponding with the external orbital angle, and one 

 posterior on the hepatic region. The dorsal keel on the 

 first segment of the abdomen is produced into an anteriorly 



