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Chologaster papilliferus. In springs of Union and Jackson counties, 
I1linois. 
Amblyopsis spelaeus. Widely distributed in underground streams in 
the Ohio valley. 
Typhlichthys subterraneus. Subterranean streams, chiefly south of 
the Ohio River. 
Typhlichthys rose. Subterranean streams west of the Mississippi. 
All have been examined except the Chologaster agassizii. Chologaster 
papilliferus possesses the most highly developed eye, but even in it there 
are many signs of degeneration; in Chologaster cornutus the outer nuclear 
and inner nuclear layers have each been reduced to a single series of cells, 
and the ganglionic layer to cells widely separated from ‘each other. The 
lens and vitreal body are still apparently normal. In all the other spe- 
cies examined the lens and the vitreal cavity are minute or absent. 
The ganglionic layer is,in Amblyopsis and T. subterraneus, a central, 
solid mass of cells; in T. rosze even this has disappeared, and the eye has 
been reduced to 0.040 mm.—0.050 mm., or to one-third the diameter of the 
eye of T. subterraneus. The result of degeneration is not the same on the 
same layers in the different. species. The degeneration is not the result 
of arrested development or of ontogenic degeneration. The eye of the 
blind fish reaching its greatest point of degeneration in T. rose, is the 
result of phyletic degeneration, begun before the fish entered the caves. 
The degenerate eye is not primarily due to the cave habitat. The eyes 
of those species living in the light are prophetic of the eyes of those living 
in the dark. 
A New Buinp Fiso. By C. H. EIGENMANN. 
[Abstract. ] 
In the caves of Missouri lives a species of Typhlichthys. It is known 
from the description of Garman of its outer form, the description of its 
habits by Miss Hoppin and from the description of its eye by Kohl. In 
external characters it is very similar to Typhlichthys subterraneus from 
the Mammoth Cave. It differs from that species widely in the structure 
of the eye. This trans-Mississippi species has been named rosz for the 
rediscoverer of the California Typhlogobius, a pioneer in the study of 
Biology among women, Mrs. Rosa Smith Eigenmann. 
