1894.] Subterranean Fauna of North America. 733 
habitat is, as far as known, quite limited. In its pink color 
and general appearance it much resembles the blind fishes in- 
habiting the caves of southern Indiana. Its peculiarities are 
doubtless due to its habits. The entire bay region is inhabi- 
ted by a carideoid crustacean which burrows in the mud. It, 
like the blind fish, is pink in color. Its holes in the bay are 
frequented by Cleavelandia, etc., while at the base of Point 
Loma, where the waves sometimes dash with great force, the 
blind fish is its associate. . . . . In the bay the gobies 
habitually live out of the holes, into which they descend only 
when they are frightened, while at Point Loma this species 
never leaves its subterranean abode, and to this fact we must 
attribute its present condition. 
“ How long these fishes have lived after their present fashion 
it would be hard to conjecture. The period which would pro- 
duce such decided structural changes can not be a brief one. 
The scales have entirely disappeared, the color has been re- 
duced, the spinous dorsal has been greatly reduced ; not only 
have the eyes become stunted, but the whole frontal region of 
the skull, and the optie nerves have been profoundly changed. 
“The skin, and especially that of the head, has become 
highly sensitized. The skin of the snout is variously folded 
and puckered and well-supplied with nerves; the nares are 
situated at the end of a fleshy protuberance which projects 
well forward, just over the mouth. At the chin are various 
short tentacles, and a row of papillae, which very probably 
bear sensory hairs similar to those represented in Figs. 15 and 
16 (Plate XXIII), extends along each ramus of the lower jaw, 
and along the margin of the lower limb of the preopercle. 
The eye is, however, the part most seriously affected. In the 
young, Fig. 7, it is quite evident, and is apparently functional. 
Objects thrust in front of them are always perceived, but the 
field of vision is quite limited. With age, the skin over the 
eye thickens, and the eyes are scarcely evident externally. As 
far as I could determine, they do not see at this time, and cer- 
tainly detect their food chiefly, if not altogether, by the sense 
of touch. A hungry individual will swim over meats, fish or 
a mussel, etc., intended for its food without perceiving it by 
