GASTEROPODA. 15 
SuccINEA RoTUNDATA (Gould). 
Testa parva, tenera, sub-opaca, hemtspherica, flavido-virens, concinné 
striata: spira feré nulla, intus aperta ; anfractibus duobus cum di- 
midio, ultimo amplissimo: apertura circularis, postice angulata, 
testam feré adequans ; margine columellari obliquo, subrecto, conspicue 
plicato, et callo lato induto. 
Succinea rotundata, Goutp; Proceed. Boston Soc. Nat. Hist., i. 
182. Nov. 1846. Expedition Shells, 27. 
AnimAL much too large for the shell, finely punctured with vermi- 
lion, with a dusky stripe along the middle of the tail, and one passing 
back from each tentacle: tentacles very much developed. 
SHELL small, very thin and fragile, of a pale russet colour, the sur- 
face very regular and smooth, crossed by very fine and rounded lines 
of growth. As it lies upon its aperture the periphery is nearly circu- 
lar, a little oval, and its back is spherically rounded. ‘There are two 
and a half whorls, the upper one forming a very minute spire scarcely 
rising above the general surface. Base rounded. Aperture nearly 
as large as the shell, somewhat angular posteriorly, displaying the 
interior of the spire; columella oblique, very slightly arcuate, having 
a distinct fold, and a broad coating of enamel across the penultimate 
whorl. Interior silvery white, calcareous. 
Greatest diameter two-fifths of an inch; least diameter seven- 
twentieths of an inch; axis three-twentieths of an inch. 
Obtained by Dr. Pickering on the mountains of Oahu, Sandwich 
Islands. 
Its general form is like that of S. putamen, but it is much smaller, 
and not angular at the periphery. 
Both are remarkable for their regularly rounded, hemispherical 
form. ‘There are no revolving strie. The lip comes off so near the 
summit of the spire that the apex is not visible, when the shell lies on 
its back. 
