120 NEW-YORK FAUNA — MOLLUSCA. 



GENUS NATICA. Bruguieres. 



Animal : head emarginate in front ; two long and pointed tentacles somewhat flattened at 

 their base : eyes sessile, at the external base of these tentacles. Mouth with a labial tooth : 

 no tongue. Foot short, deeply bilobed across in front, exhibiting behind a lobed appendix 

 supporting the opercle. Shell smooth, subglobose or orbicular, umbilicated ; spire sub- 

 depressed ; aperture entire, semicircular ; inner lip with a callus which modifies the umbi- 

 licus, not toothed ; lip sharp, smooth within. 



Obs. Some shells have been referred to this genns, without an umbilicus ; these constitute 

 a subgenus, for which the names Globulus and Globularia have been proposed. 



Natica heros. 



PLATE VII. FIG. 148. — FIG. 149. Egg-case. 



Natica heros. Say, Journ. Acad. Nat. Sciences, Vol. 5, p. 248. 

 If. id. Russel, Essex Journal of Nat. Hist. Vol.1, p. 67. 



N. id. Gould, Invertebrata of Mass. p. 233, fig, 165. 



Description. Shell large, thick, globular-ovate. Whorls five, convex : spire considerably 

 elevated. Aperture oval ; the callus reflected over a small portion of the large, patulous, and 

 coarsely wrinkled umbilicus. 



Color. Epidermis thin and yellowish ; beneath this, dark reddish mixed with ashen. 

 Aperture dark reddish brown, occasionally tinged with yellowish. 



Length, 2" 5. Diameter, 2'0. 



This is the largest species of the genus, and although found every where along our coast, 

 is less numerous than the following. It is exceedingly voracious, devouring dead fishes, etc., 

 and sometimes reaches to a large size. Dr. Gould speaks of one five inches long, with a 

 breadth of three and three-quarter inches. On the plate 7, fig. 149, is a drawing of a singularly 

 shaped production, which is intended for the protection of the eggs of this and perhaps the fol- 

 lowing species. It usually occurs in the form figured above, resembling remotely the glass 

 shade of an astral lamp, but the circle is never complete. It is composed of an aggregation of 

 fine particles of sand, connected together by some glutinous substance. It is solid and brittle 

 when found on the dry shore ; but when immersed in water, it becomes as flexible as leather : 

 the ova appear to be deposited on the under side. This singular egg-case has long been a 

 puzzle to naturalists, and its true character was first established by Mr. Hogg, who identified 

 similar productions by hatching them from the N. glaucina of Europe. 



