706 Bulletin 47, United States National Museum. 



" Crooked streams are not so impassable as one might suppose, even to floating objects, insects, 

 mollusks, etc. A twig or leaf dropped into the current on the inside of the upper arm of a 

 horseshoe curve in a stream is carried near to the opposite shore before it leaves the bend, and, 

 especially if favored by the wind, is often carried completely across. The passage is much easier 

 to animals that swim, however feebly. Taking everything into the account, it does not appear 

 to be at all necessary to credit Typhlichthys subterraneus from Kentucky, Tennessee, and Missouri 

 with more than a single point of origin. The same may be said of Amblyopsis spelseus of Ken- 

 tucky and Indiana, and of the blind crayfish of the same States. 



" In an article entitled ' Life in the Wyandot Cave,' Ann. Mag. Nat. Hist., Ser. 4, vm, 1871, p. 

 368, Professor Cope makes this statement concerning Amblyopsis: ' If these Amblyopses be not 

 alarmed, they come to the surface to feed, and swim in full sight, like white aquatic ghosts. 

 They are then easily taken by the Land or net, if perfect silence is preserved ; for they are 

 unconscious of the presence of an enemy, except through the medium of hearing. This sense, 

 however, is evidently very acute, for at any noise they turn suddenly downward and hide 

 beneath stones, etc., on the bottom.' The statement is repeated in Amer. Nat., 1872, p. 409. 

 Such a development of this sense, in recesses where we are accustomed to think any sounds other 

 than those made by the rippling or dripping water are almost unknown, is not what one would 

 have expected. Having this in mind, I wrote to Miss Hoppin, asking her to make experiments 

 on Typhlicldlnjs, and to determine what she could in regard to hearing, feeding habits, etc. The 

 quotations here given are from her replies: 



" ' For about two w r eeks I have been watchinga fish taken from a well. I gave him considerable 

 water, changed once a day, and kept him in an uninhabited place subject to as few changes of 

 temperature as possible. He seems perfectly healthy, and as lively as when first taken from the 

 well. If not capable of long fasts, he must live on small organisms my eye can not discern. He is 

 hardly ever still, but moves around the sides of the vessel constantly, down and up, as if need- 

 ing the air. He never swims through the body of the water away from thesides, unless disturbed. 

 Passing the finger over the sides of the vessel under water, I find it slippery. I am careful not 

 to disturb this slimy coating when the water is changed. * * * Numerous tests convince 

 me that it is through the sense of touch, and not through hearing, that the fish is disturbed: I 

 may scream, or strike metal bodies together over him as near as possible, yet he seems to take no 

 notice whatever. If I strike the vessel so that the water is set in motion, he darts away from 

 that side through the mass of the water, instead of around, in his usual way. If I stir the 

 water, or touch the fish, no matter how lightly, his actions are the same.'" [Carman, Bull. 

 Mus. Comp. Zobl., xvn, No. 6, 1889, 232.] 



323. AMBLYOPSIS, De Kay. 



Amblyopste, DEKAY, New York Fauna: Fishes, 187, 1842, (spelsEus). 



Eyes rudimentary, concealed under the skin and not functional. Sur- 

 face of head and body crossed by vertical tactile ridges. Gill membranes 

 fully joined to isthmus. Ventral fins present, quite small, close to anal. 

 One pyloric ccecum. Colorless fishes of small size, inhabiting the cave 

 streams in the limestone regions of the Ohio Valley. (a/u,(3hv(; , obtuse; 

 ch/uf, vision.) 



1048. AMBLYOPSIS SPEL^EUS, De Kay. 



(BLINDFISH OF THE MAMMOTH CAVE.) 



Head 3 in length ; depth 4|. D. 9 ; A. 8 ; V. 4 ; P. 11. Body and head 

 covered by fine ridges of tactile papillae. Colorless. Mouth comparatively 

 large, the length of its cleft about equal to base of dorsal. Pectorals reach- 

 ing front of dorsal ; caudal long, rather pointed. Length 5 inches. Subter- 

 ranean streams of the limestone region of Kentucky and southern Indiana ; 

 not rare ; most common in the River Styx of the Mammoth Cave. Very 

 tenacious of life and readily kept in aquaria, (spelceus, pertainingto caves.) 

 Amblyopsis spelsew, DE KAY, N. Y. Fauna: Fishes, 187, 1842, Mammoth Cave, Kentucky; 

 GATHER, Cat., vii, 2, 1868; PUTNAM, Amer. Nat., 1872, 30, fig.; JORDAN & GILBERT, Synop- 

 sis, 324, 1883. 



