231 



APPENDIX. [By T. A. Conrad.] 



Among Mr. Say's manuscripts I find the following observation 

 and description of a new species of Chiton, wliicli it is deemed 

 proper to publish at the present opportunity. — Ed. 



Venus cingenda, Dillw. 



Venus cancellata, Lam. 



Having obtained numerous specimens of this variable shell, \ 

 find that my V. elevata must be placed as a variety of it. 



Chiton apiculatus.— Valves eight; dorsal triangles with series 

 of elevated points; lateral triangles with scattered elevated points. 



Inhabits the coast of South Carolina. 



Whitish ; oval-oblong, convex, subcarinated ; eight valved ; an- 

 terior valve with numerous, separate, elevated, equal, sub-equi- 

 distant points ; the six following valves have on their dorsal 

 triangles from twenty to thirty longitudinal series of equal, elevated, 

 approximate rounded points ; their lateral triangles with elevated 

 points, as on the anterior valve ; posterior valve at base like the 

 dorsal triangles, and its broad margin with the points like those of 

 the anterior valve. Length nearly half an inch. 



This very pretty species was sent to me from Charleston by Dr. 

 Ravenel, of that city, who informs me that it is so rare that he 

 has not found more than this specimen, which he has been so 

 liberal as to present to me. The regular, longitudinal series of 

 elevations on the dorsal triangles, resemble so many minute strings 

 of pearl. 



[Addenda.] 



[The following generic descriptions were omitted in the " Description.* 

 of Terrestrial Shells."— Ed.] 



Genus Helix.* — Shell subglobose, suborbicular, broader than 

 long, spire convex ; aperture wider than long, diminished above by 

 the convexity of the penultimate whorl. 



Obs. The shells belonging to this genus are terrestrial, often in- 

 habiting moist places; they are thin, brittle, and translucent; the 

 young shells are umbilicate almost invariably. 



Grenus PuPA.f — Shell spiral produced. Aperture contracted, 



[* Nicholson's Encyclopedia. — Ed.] ' 



[t Nicholson's Encyclopedia 3d ed. Odostomia of 1st and 2d. ed. — Ed.] 



