THE BLIND FISHES OF MAMMOTH .CAVE. 23 
blyopsis and Typhlichthys by the presence of eyes, the absence of 
papillary ridges on the head and body, and by the longer intestine 
and double the number of pyloric appendages, as well as by the 
position of the ovary; and agrees with Typhlichthys by the ab- 
sence of ventral fins. Amblyopsis and Typhlichthys are nearly 
colorless, while Chologaster Agassizii is of a brownish color similar 
to many of the minnows, and C. cornutus is brownish yellow, with 
dark, longitudinal bands. 
Among the most interesting points in the history of this genus 
is the fact of its occurring in two widely different localities, C. 
Agassizii having been found in a well, in the same vicinity (proba- 
bly in the same well) with a specimen of Typhlichthys, and 
undoubtedly belonging to the same subterranean fauna west of the 
Appalachian ridge, while C. cornutus belongs to the southern coast 
fauna of the eastern side of that mountain chain, and is thus far 
the only species of the family known beyond the limits of the great 
subterranean region of the United States. 
Having now given an outline of the structure, habits and distri- 
bution of the four species belonging to the family, and recapitu- 
lated the known facts, we are better able to consider the bear- 
ings of the peculiar adaptation of the blind fishes, in the Mañ- 
moth and other caves, to the circumstances under which they exist. 
Prof. Cope in stating, in his account of the blind fish of the 
Wyandotte Cave, “that the projecting under jaw and upward di- 
rection of the mouth renders it easy for the fish to feed at the sur- 
face of the water, where it must obtain much of its food,” suggests 
that : — 
“ This atrnctaie also probably explains the fact of its urag the 
sole representative of the fishes in subterranean waters. No doubt 
many other forms were carried into the caverns since the fae 
first found their way there, but most of them were like those of 
our present rivers, deep water or bottom feeders. Such fishes 
would starve in a cave river, where much of the food is carried to 
them ‘on the surface of the stream. ..... The shore minnows 
are their nearest allies, and many of them have the upturned 
mouth and flat head. ..... Fishes of this, or a similar family, 
enclosed in subterranean waters ages ago, would be more likely to 
live than those of the other, and the darkness would be very apt 
to be the cause of the atrophy of the organs of sight seen in the 
Amblyopsis.” 
This suggestion was undoubtedly hastily made by Prof. Cope 
when writing the letter which was printed in the ‘Indianapolis 
