350 Descriptions of some Shells, &c. 
Genus Bulla, Lin. 
B. insculpta. Fig. 4 
Shell, small, white, very thin and fragile, pellucid, oval, impres- 
sed at top, regularly rounded and widest below; with many slight 
longitudinal wrinkles, a few obsolete longitudinal waves, and very 
numerous equal, straight, impressed, revolving lines: spire none ; 
in lieu thereof, a pit, not deeper than the origin of the right lip: 
aperture, of nearly equal width for one third of its length from the 
top, thence, downward, gradually expanding to a considerable 
breadth: right lip, regularly arched, sharp, rising from the axis, 
with a regular curvature upward and forward, bigher than the shoul- 
der of the shell: left margin, above, a thin plate glued upon the 
convexity of the second turn, below, rolled into a kind of spiral 
pillar which is twisted around, and at a little distance from, the im- 
aginary axis of the shell. Axis, void to the summit, where it is 
closed by the common origin of the two margins: no proper wm- 
bilicus, but a slight chink under the recurved plate which forms the 
pillar. 
Length, 0.35 of an inch. 
Breadth, 0.23 do. 
Inhabits muddy bottom in Newport harbor, (R. I.) Dredged in 
about fifteen feet of water. 
This can hardly be Say’s B. solitaria, (Journal of the Academy 
of Nat. Sciences, Phil., Vol. I, p. 245.) It is not, umbilicated at 
top, as that species is; having merely a shallow pit in which noth- 
ing of the interior whirls can be seen. The solitaria is described 
as being “‘ narrowed at the base ;” but though our shell is regularly 
rounded in the passage, below, of the right into the left margin, it 
is widely rounded; and the widest part of the shell is below the 
middle. 
B. oryza. Fig. 5. 
Shell, very small, white, glossy, not very thin, translucent, ellipti- 
cal, a eilly diminishing upward and downward from the mid- 
base being rather acute and the summit depressed into a 
shallot pit: surface, with numerous longitudinal wrinkles, a number 
of impressed revolving lines on the lower portion, and a few more 
obscure revolving lines near the shoulder—none of these wrinkles 
or lines being visible without a magnifier: aperture, narrow at top, 
and gradually widening toward the base: right lip, regularly arch- 
