CRAYFISHES FROM ALABAMA CAVES — RHOADES 



147 



and body proportions. However, the eyes are normal, the antennae 

 are shorter, and the antennal scale is much narrower. The sides of 

 the rostrum converge more strongly, and there is no trace of a 

 median carina. The lateral spines of the carapace are small and 

 acute. The annulus ventralis is bisected by a deep median furrow 

 which curves strongly to the observer's left to form a large blunt 



B 



Figure 36. — Cambarus cahni, new species: A, Dorsal view of carapace; B, annulus ventralis; 

 C, gonopod, male, form II, outer view; D, gonopod, male, form II, inner view. 



lobe. I do not place this record with C. cahni since the specimen 

 at hand bears greater affinity to the "Section of G. extraneus'''' than 

 to the "Section of C. hamulatusP 



Distribution. — C. cahni is known only from the type locality, but 

 it will probably be found distributed over the limestone cave region 

 of northern Alabama where cave ecology is suitable. Belgreen Cave 

 is a small cave with a very deep underground stream. The stream 

 becomes muddy and almost fills the cavern in wet seasons. 



