[From the American Journal op Science and Arts, Vol. IX, June, 1875.] 



16. The Crustaceans of the Caves of Kentucky and Indiana ; 

 by S. I. Smith. — Through the courtesy of Dr. Packard of Salem, 

 Mass., I have recently been enabled to examine the types of his 

 Crangonyx vitreus from near Orleans, Ind., and also several 

 specimens of an amphipod collected in Mammoth Cave by him- 

 self. All the specimens from Mammoth Cave are of a single 

 species, which, there can be little doubt, is really the Stygobro- 

 mus vitreus unintelligibly described from the same locality by 

 Professor Cope. The species is really a Crangonyx and it should 

 stand as G. vitreus, although very different from the one from 

 Indiana which is referred to Cope's species by Dr. Packard and 

 by him called C. vitreus. It is a small species, the largest 

 specimen being less than a fourth of an inch (5*2 mm.) long, ap- 

 parently wholly eyeless, and remarkable for the rudimentary 

 character of the unibranched posterior caudal stylets, which are 

 shorter than the telson. It seems to be near the typical species 

 described by Bate, and it is closely allied in some respects to C. 

 tenuis, also an apparently eyeless species, which I have described 

 from wells at Middletown, Conn. Since this note was first 

 written, I have examined several specimens of this last species, 

 collected by Mr. J. K. Thacher, under stones in a small brook, 

 near New Haven. From this it seems not at all improbable that 

 the allied species from Kentucky and Indiana — and very likely 

 also the eyeless, cave species of other groups — may still be found 

 in the surface streams of the same region. 



The specimens of Dr. Packard's species from Indiana are badly 

 preserved but are suffi cient to show that the species is very closely 

 allied to Crangonyx gracilis, from Michigan, Lake Superior, etc., 

 differing principally in the structure of the eyes, which are well 

 developed and abundantly supplied with black pigment in C. gra- 

 cilis, while in Dr. Packard's specimens they are observable with 

 difficulty, are wholly without black pigment, are undoubtedly 

 colorless in life, and are probably only imperfect organs of vision, 

 although the structure of the facets can be distinctly made out. 



