STALK-EYED CRUSTACEA 399 



Synopsis of the Genera. 



I. Abdomen simply bent. 



A. Eyes normal. 



a. Rostrum flattened, of moderate breadth. Carapace 

 with pubescent transverse stris ; cardiac area not 

 prominent. Abdominal segments unarmed. — (Ga/at/iea.) 



b. Rostrum slender, styliform, with well-developed 

 supraorbital spines. Carapace usually with spines ; 

 cardiac area usually distinctly circumscribed. One or 

 more of the abdominal segments with spines on anterior 

 dorsal margin. — {MtDiida.) 



B. Eyes nonpigmented. 



c. Eye-peduncles usually prolonged beyond cornea. 



c^. Rostrum spinulose, usually more or less triangular ; 

 margins rarely dentate or spinose. Carapace rugose, 

 spinose, or glabrous, Antennal peduncle usually stout. — • 

 {Mimidopsis.) 



d}. Rostrum flattened or triangular. Carapace un- 

 armed. Antennal peduncle of moderate width. — 

 {Elasmojiotus.) 



d. Eye-peduncles not prolonged beyond cornea ; cornea 

 terminal. Rostrum long, spinulose. Carapace broad, 

 convex from side to side, armed with four spines on 

 dorsal surface. Antennal peduncle usually stout, — 

 {Galacantha.) 



II, Abdomen folded on itself. 



e. Rostrum slender and spiniform, usually upturned. 

 Eye-stalks with dilated cornea. No acicle on antennal 

 peduncle. — {Ptychogaster.) 



f. Rostrum flattened and acute. Cornea scarcely 

 dilated. Acicle present on antennal peduncle. — 

 {Uroptychus.) 



