PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 529 



Caves, in Giles CouDty, Virginia, curiously enougli, is not blind. This 

 is paralleled in the case of two species of spiders, however, which were 

 collected for me in a cave in Oregon, over a year ago, by Professor Cope. 

 In one of them there is not a vestige of the eyes remaining, while in the 

 other they are well developed. A Myriapod, which appears to be a 

 Julus, from the same cavern also has eyes. The Polydesmus cavicola 

 Pa('kard, from a cave in Utah, seems to have well-developed eyes. The 

 Orchesella c(eca^ which still remains to be fully described, has very un- 

 developed eyes, but differs in no other essential from its congenors. It 

 was also collected in an Oregon cavern by Professor Cope. Multitudes 

 of facts might be added, but the subject is too large a one for hasty gen- 

 eralizations, and must be approached with the same thoroughness of 

 purpose which has characterized the work of Messrs. Darwin and Wal- 

 lace in their essaj'S m\}0\\ kindred subjects relating to the origination of 

 species. We may be allowed, however, to add that, in the absence of 

 proof to the contrary, with the increase in the number of known blind 

 forms which are often congeneric with light-loving species, there is the 

 strongest kind of ground for supposing that they have descended from 

 forms which had eyes, and which wandered into these recesses, where, 

 after many generations had lived and died, a blind form appeared, 

 which resulted from the gradual abortion of tlie visual organs of its 

 ancestors. In proof of this we have the partially blind Orchesella, which 

 now seems to be verging towards such a condition. In the absence of 

 a greater number of facts we are not justified in inferring more. True, 

 we have a few instances amongst the mollusks, some of which in their 

 larval states have useful ej^es, but which afterwards become useless and 

 abort as the shell develops and gets thicker. Some terrestrial Myria- 

 pods are blind, such as Eurypauropiis; so is Lumhricus, the earth-worm, 

 and some of the dirt-abiding Thysanura, which also live among fallen 

 leaves, such as Campodea, while in the burrowing Symphyla {scolopen- 

 drelke) the eyes are reduced to a single pair, with little or no red or dark 

 coloring in the tapetum, differing widely in this respect from the com- 

 pound-eyed, terrestrial Myriapods. 



DESCRIPTBOIV OF A NE'W SPECBES OF PRIONOTUS (PKIOIVOTt'S 

 S^JES»I;IAN©PIIKYS,S FKOM THE COAST OF OAI^IFOKIVIIA. 



By ^T. N. I.O<CM5WClTOIV. 



Prionotns stephanophrys, sp. no v. 



L. lat. 53 ; D. 10-12 ; A. 11 ; P. 12 ; Y. 1-5 ; C. 3-1-8-1-3. 



Body less elongate than in P. caroUnus, head not quite three and a 

 half; greatest depth five and a third times in total- length. Greatest 

 depth under third dorsal ray. 



Snout concave in profile ; forehead convex immediately in front of eye, 

 from which to the origin of the dorsal fin the i>rofile rises in almost a 

 Proc. Nat. Mus. 80 34 Apa'ill 18, 1881. 



