64 STALK-EYED CRUSTACEA 



forwards. There is a prominent spine at the internal 

 angle of the eye, and a small spine at the external 

 canthus. The external antenna; are cylindrical. There 

 is a spine on their external edge, and one lower down, 

 directed downwards. 



The first pair of legs is short and granular. There 

 is a short spine at the base of the arm. The first pair 

 of walking legs is one and a half times as long as the 

 body. 



Range. — West Indian Sea. 



B. Rostnun composed of tivo distinct spines. 

 b. Basal joifit of externa! antennc^ witJiont a spine at 

 its distal end : — 



2. Scyra. 

 Scyra ... A. Milne Edwards, Dana. 



Carapace triangular, tuberculated. Praeocular spines 

 present. Spines of rostrum lamellate at base, acute at 

 distal end. Basal joint of external antenna; straight, 

 narrow ; its extremity is exposed upon the sides of the 

 rostrum. The second joint is flat, and longer than the 

 third. First pair of legs rather long ; palm carinated. 

 Walking legs not compressed. 



Range. — Atlantic and Pacific Ocean ; in deep water. 



I. Scyra umbonata. 



Scyra unibonata . Stimpson, A. Milne Edwards. 



The carapace has six flat protuberances on its surface, 

 situated one on the posterior part of the gastric region, 

 one upon the cardiac region, and two on each branchial 

 region. These last have outside a sharp and triangular 

 tooth, directed forwards and outwards. All are not 



