18 PROCEEDINGS OF THE SCIENTIFIC ASSOCIATION, 
§ 1 .—Descriptions of new Species. 
Gundlachia crepidulina. n. sp. 
Shell elongate-oval, slipper-shaped, horny: covered be- 
neath. by a whitish convex diaphragm, having a rounded 
or oval aperture at the anterior end ; right side almost 
vertical, left side gently sloping. 
In the American Journal of Conchology, 1870, p. 3 1 1 r 
I described a shell under the name of Ancylus texiilis. 
Prom certain characters given by me, my friend Mr. 
Thomas Bland suggested that this might be a Gundlachia. 
I have, since then, devoted some labor to the investigation 
of the subject, and although I have not succeeded in 
clearing up all the points of difficulty, I think that I am 
justified in describing both an Ancylus and a Gundlachia 
as inhabitants of our fresh waters. I have found addi- 
tional examples of both forms. For the present, therefore, 
the name Ancylus textilis may be reserved for the shells 
agreeing with the specific description given in the Ameri- 
can Journal of Conchology, and with the figure 9 of plate 
17 therewith. To the Gundlachia figured under the num- 
ber 1 1 on the same plate, and described here, the name 
of crepidulina may be attached. I have found no addi- 
tional examples of the form represented in fig. 10 of the 
plate accompanying my paper in the American Journal 
of Conchology. 
Amphibulima ( Omalonyx) felina n. sp. 
Animal almost smooth, of a slightly yellowish white, 
wariegated with small spots, and streaked with two lines 
of cinereous purple extending from the two oculiferous 
tentacles to the point of the foot behind; mantle covering 
