NO. 1285. FA UNA OF MAMMOTH CA VE—IIA Y. 235 



These conditions point to the conclusions: First, that O. hartoiil tene- 

 hi'osus is a permanent resident of Mammoth Cave; second, that it has 

 lived there long- cnoug'h to have diverged markedly from its relations 

 on the surface; third, that it has been affected not only by the general 

 spelean conditions, but those peculiar special conditions of Mammoth 

 Cave; fourth, that it is not the ancestral type from which C. i-xjlluci- 

 (his has sprung; fifth, that the two species are proba})Iy to a great 

 degree inimical to each other, and, sixth, that the idea that the two 

 species interbreed is an erroneous one. 



That specimens have been taken, as I was told at the cave, which 

 were quite white but otherwise like C. hartoni fenehrosus, I do not 

 doubt, but I regard such individuals as albinos. 



Kegarding the relationship of O. pellncidus testi Hay, I will say 

 that so far as is known this subspecies is found in a very small area 

 in Indiana at the very northern limits of the range of 0. •pelhicidtis. 

 C. hartoni occurs in the same cave, but it does not resemble the blind 

 species in any wa}', and has not even characters b}^ which we can mark 

 it as a permanent resident. Were the conditions reversed and C. 

 hartoni tenelyro-ms found anywhere in company with C. pellucidus 

 testi there might be some grounds for regarding them both as possi- 

 ble intermediates between C. pellucidus and C. hartoni^ but under 

 conditions as they exist such a view is untenable. 



The surface inhabiting individuals of C. hartoni from the neigh- 

 borhood of Mammoth Cave are plainly the stock from which the cave- 

 inhabiting individuals have descended. In proportions of the body, 

 outline, etc., they agree with the cave variety and differ very mark- 

 edly from the varieties of C. hartoni found in Indiana and Tennessee. 



CAMBARUS DIOGENES Girard. 



In a collection received from Mr. Edward Hawkins, one of the 

 guides at the cave, there were eight specimens of this species, includ- 

 ing females and males of both forms. They agree in shape of rostrum 

 and form of chelipeds Avith specimens from Indiana, the former having 

 thickened and quite strongly converging margins; the chehe are short 

 and broad and the movable finger is rather deepl}^ excavated at the 

 base. 



CAMBARUS PROPINQUUS Girard. 



A few small specimens which appear to l)elong to this species were 

 obtained from pools and shallow chaiuiek along Green River. 



CAMBARUS RUSTICUS Girard. 



A large number of small individuals of this species were collected 

 in Green River l)etween Manmioth Cave and Ganters Cave. Almost 

 all the males were in the second form. They differ from the typical 

 C. rasticas slightly in the g-reater development of spines, those of the 



