252 AMERICAN JOURNAL 



black; mantle with a narrow, brown, thickened border, with mi- 

 nute serrations corresponding to the strise, and dots to the rays 

 of color, of the shell ; furnished with minute cilia on the extreme 

 edge. Tentacles short, ruther slender, almost black, tips under 

 side and swollen base, whitish. Eyes very small, on outer bases 

 of tentaculfe ; head small, very dark slate color or blackish; 

 muzzle short, dark ; frill light yellowish white, crenate ; disk 

 dark, granulose, with a few papillge on the upper anterior edge ; 

 mouth rounded. Gill very long, narrow and slender, attached 

 to the under surface of the hood on the left side before the com- 

 missure of the neck and mantle ; pointing toward the right. 

 Anal papilla prominent, infra-anal smaller; renal orifice exceed- 

 ingly minute, circular. Formula ns in the last. 



The color of this shell varies from almost black to light yellow 

 brown : there is a variety of ■patina which closely approaches 

 the dark variety. 



It is also one of the more southern forms ; two or three of the 

 dark colored form were obtained at Victoria, Vancouver's Island, 

 by Robert Kennicott. I have others from Port Orford, W. T. 

 (Capt. E. E. Smith), and Stearns reports it from Bodega and 

 Baulinas Bays. It is common near the heads of San Francisco 

 Bay, and abundant at Monterey ; yet in all these localities it is 

 less plentiful than C. peJtn or patina. It ranges southward to 

 Lower California, and possibly to Mazatlan. 



COLLISELLA ASMi, Midd. sp. Plate 14, fig. 7. 



Patella a5';;w, Midd., Mai, Ross, ii, p. 39, No. 13, pi. 1, fig. 5. 



Soft parts dark green. Mantle with a narrow thickened edge. 

 Foot small, oval. Head very small. Formula, 2. 



The above notes were taken from a dry specimen kindly com- 

 municated by Dr. Carpenter, from w^hich the radula was ob- 

 tained. 



This species has long been a puzzle to conchologists. Most of 

 them have regarded it as a variety, caused by a peculiar habitat, 

 of some other species.* I am inclined to regard it as distinct, 

 as the teeth show differences in detail from any of the other 

 species. I have seen a few specimens of pelta and patina in 

 which the apex was elevated, conical and black, which were sup- 

 posed to be proof that asmi was onl}'' a form of one of 

 them ; but I confess I Avas unable to see that the malformed 

 pelta or patina had anything more than a slight resemblance to 



* Mr. Jeffreys suggests (Brit. Conch, iii, p. 249) that it is a variety of 

 Acmcea virginea, but it has hardly a character in common with it. 



