438 



STALK-EYED CRUSTACEA 



piliferous groove interrupted in the middle line. The 

 second pair of legs slightly longer than the third pair. 



The colour is green-violet, spotted irregularly with 

 yellow on the thorax, fasciated with yellow on the legs. 

 Each abdominal segment near its posterior border has 

 a yellow band and some circular spots, of which two on 

 the second segment and two upon the sixth segment are 

 very large and are bordered with green. 



Range. — West Indies. 



Tribe II. Astacidea. 



Astacidea . . . 

 Macroura astacina 



Dana, Miers, Spence, Bate. 

 De Haan. 



Carapace often marked with a dorsal transverse suture, 

 with the longitudinal sutures obsolete. Basal scale of 

 external antennae small, obsolete, or large and well de- 

 veloped. First pair of legs stout, didactyl or monodactyl. 



Family I. Eryonidae. 

 Family II. Homaridae. 

 Family III. Astacidae. 



Synopsis of the Families. 



I. No rostrum present. 



A. The first three pairs, sometimes the 

 first four pairs, or all the legs, have pincers ; 

 the posterior pair of legs directed back- 

 wards. — {Eryon id a. ) 



II. A rostrum present. 



B. First three pairs of legs have pincers ; 

 the first pair the largest. 



EryonidiC, 



