122 NEW-YORK FAUNA MOLLUSCA. 



Natica IMMACULATA. 



PLATE VII. FIG. 146. 



Natica immacuUta. ToTTEN, AmPrican Journ. Science, Vol. 29, p. 351, fig. 6. A. B. C, 

 N. id. GooLD, Invertebrata of Mass p. 234, fig. 108. 



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. Tolten, by dredging in deep water near Newport, 

 Rhode-Island. It has since been obtained from the shores of Massachusetts, and, according 

 to Mr. Whealley, 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. 



Natica clausa. 



PLATE VII. FIG. 150. 



N. clama. SowERBY, Zool. Joum. Lond Vol. 4, p. 360, 



N, consolidala. CouTHOUv, Bost. Journ Nat. Hist. \ol. 2, p. 89, pi. 3, fig. 14- 



JV. clausa. Gould, 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 strias. 



Color. Epidermis thin, greenish brown ; underneath varying from dull white to dark reddish 

 or brown. Opercle milk-white ; throat white. 



Length, • 3 - ■ 5. Width, • 4 - ' 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 consolidate, 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. 



