DECAPOD CRUSTACEANS OF THE WEST INDIES 57 



2. Eyes reduced, cornea limited to distolateral pigment spot on eyestalk; pereio- 



pods with exopods; subterranean species 3 



Eyes normal, cornea nearly as broad as or broader than eyestalk; pereiopods 

 without exopods; epigean species 4 



3. Exopod on fifth pereiopod nearly as well developed as those on preceding 



ones Typhlatya garciai (p. 80) 



Exopod on fifth pereiopod greatly reduced, barely discernible. 



Typhlatya monae (p. 80) 



4. Rostrum with dorsal teeth Micratya poeyi (p. 70) 



Rostrum without dorsal teeth 5 



5. Carpus of second pereiopod broader than long 6 



Carpus of second pereiopod much longer than broad 8 



6. Adults without horizontal lateral lobe or tooth on either side of rostrum; 



third pereiopod not bearing horny scales or tubercles and only slightly 



more robust than fourth pereiopod Atya lanipes (p. 62) 



Adults with distinct horizontal lateral lobe or tooth on either side of rostrum; 

 third pereiopod bearing prominent horny scales or tubercles and con- 

 siderably larger and more robust than fourth pereiopod 7 



7. Lateral lobes of adult rostrum obtuse (fig. 10a) ; pleuron of second abdominal 



somite without blunt marginal spines although pleura of third to fifth 

 somites may bear acute marginal denticles (fig. 10c); body without 



transverse bands of dark color. Atya innocous (p. 57) 



Lateral lobes of adult rostrum subacute and directed anteriorly (fig. lOd); 

 ventral margins of pleura of second to fifth abdominal somites armed with 

 row of small blunt spines (fig. 10/); transverse bands of dark color at 

 juncture of carapace and abdomen and on anterior part of sixth abdominal 

 somite Atya scabra (p. 63) 



8. Orbital margin minutely serrate; appendix masculina on second pleopod of 



male slender, terminating in sharp point (figs. 14/, g) . . Jonga serrei (p. 66) 



Orbital margin not serrate; appendix masculina on second pleopod of male 



broad, rounded distally 9 



9. Appendix masculina widening distally, about three-fourths as wide as long, 



posterior margin slightly and evenly convex (fig. 19a). 



Potimirim americana (p. 76) 

 Appendix masculina widest proximally, not more than half as wide as long, 



posterior margin sinuous 10 



10. Dorsal margin of rostrum curving downward at tip; appendix masculina 

 with deep, unarmed sinus in posterior margin (fig. 19c) . 



Potimirim glabra (p. 76) 



Dorsal margin of rostrum nearly straight; appendix masculina without deep, 



unarmed sinus in posterior margin (fig. 19d). . Potimirim mexicana (p. 79) 



Genu8 Atya 

 6. Atya innocous (Herbst) 



Figures 8, lOa-c, 14a, b 



Astacus Nasoscopus Meuschen, 1778, p. 86 [type-Iocahty : Martinique; publication 

 ruled invalid by Opinion 260, International Commission on Zoological 

 Nomenclature]. 



Cancer (Astacus) Innocous Herbst, 1792, p. 62, pi. 28: fig. 3 [type-locality: Mar- 

 tinique]. 



