122 NEW-YORK FAUNA — MOLLUSCA. 
NaTICcA IMMACULATA. 
PLATE VII. FIG. 146. 
Natica immaculata. ToTrEeN, American Journ. Science, Vol. 28, p. 351, fig. 6. A. B. C. 
N. id. Goutp, Invertebrata of Mass. p. 234, fig. 168. 
N. id. WHEATLEY, Cat. Shells of U. S. No. 695. 
Description. Shell small, solid, longitudinally suboval. Whorls about five, the upper ones 
very slightly convex: apex short and pointed ; suture not impressed ; the body-whorl convex, 
and elongated beneath. Aperture narrow, regularly and somewhat acutely curved at the 
base. Umbilicus rounded and deep, scarcely modified by the callus, which is not very 
copious, but forms a deposit under the upper part of the lip, and causes a white spiral line 
to appear externally just below the suture. Opercle horny. 
Color. Epidermis thin, greenish yellow ; underneath this, milk-white, immaculate. 
Length, 0°28. Width, 0°22. 
This species was first obtained by Col. Totten, by dredging in deep water near Newport, 
Rhode-Island. It has since been obtained from the shores of Massachusetts, and, according 
to Mr. Wheatley, it occurs from Maine to New-York. It is one of the smallest species of 
the genus, although it has been seen nearly half an inch long. 
NAaATICA CLAUSA. 
PLATE VII. FIG. 150. 
N. clausa. Sowersy, Zool. Journ. Lond Vol. 4, p. 360. 
NN. consolidata. CouTuovy, Bost. Journ Nat. Hist. Vol. 2, p. 89, pl. 3, fig. 14- 
NN. clausa, Gouup, Invertebrata of Mass. p. 238, fig. 167. 
Description. Shell subglobose. Whorls four or five, subconvex, partially flattened, or even 
concave near the sutures: spire very short, obtuse: suture distinct; aperture oval, widest 
above ; lip sharp, thickened and rounded towards the umbilicus ; callus depressed, enlarged 
at the upper angle, and in mature specimens quite concealing the umbilicus. Opercle cal- 
careous, smooth, with microscopic radiating striae. 
Color. Epidermis thin, greenish brown ; underneath varying from dull white to dark reddish 
or brown. Opercle milk-white ; throat white. 
Length, 0°3 —0°5. Width, 0°4 — 0°55. 
This arctic species has not yet been observed on our shores, although it has been obtained 
from the stomachs of fishes along the coast. It was first detected by Mr. Couthouy of Bos- 
ton, who named it consolidata, without being aware of the previous labors of Messrs. Bro- 
derip and Sowerby on this subject. It will, in all probability, be detected in the stomachs of 
fishes along the coast of New-York. 
