STALK-EYED CRUSTACEA 439 



a. Rostrum narrow, armed with many teeth. — 

 {Ho mar idee.) 



Hontarida 



b. Rostrum depressed, armed with few teeth. — 



{Astncidcc?) 



AstacidcE. 



Family I. Eryonidae. 



EryonidcB . . . Spence Bate. 



Carapace depressed, with the lateral margin serrate, 

 and broader than the abdomen. No rostrum. Eyes 

 wanting or abnormal. The internal antennae have two 

 multiarticulate flagella. The external antennje have a 

 basal scale and a long multiarticulate flagellum. The 

 maxillipedes are pediform. Legs seven-jointed ; first 

 three pair, sometimes the fourth pair, or all the legs, 

 chelate ; posterior pair reversed. Abdominal appendages, 

 except the first and sixth pair, have a small process 

 attached to the inner branch ; no division in the outer 

 branch of sixth pair. Telson tapering. 



Synopsis of the Genera. 



A. First four pair of legs with pincers; first pair the 

 largest. — (Po/j/c/ie/es.) 



B. All the legs more or less armed with pincers. — 

 (Pentac/ie/es.) 



