BERTINIA. 189 



the margins of the shell. Interior straw yellow, shading toward the 

 margin into a bluish-white. Length 1'3, width I'l, alt. '5 inch. 

 (Qabb.}. 



Santa Barbara Island, California, on the shore (Dr. Cooper). 



Tylodina (7) fungina GABB, Proc. Cal. Acad. Sci., iii, p. 188 



(1865). 



Soft parts unknown. The above measurements are approximate, 

 making allowance for the epidermis which in the dry specimen is 

 contracted and incurved around the margins to a width of about a 

 tenth of an inch. A single specimen, fresh, though without the 

 animal, was found by Dr. Cooper. (Gabb~). 



Tylodina excentrica Ijocard=Gadinia. 



Insufficiently known or spurious species. 

 Genus Bertinia Jousseaume, 1883. 



Bertinia Jouss., Bull. Soc. Zool. France for 1883, 3d. pt., p. 194 

 (type B. bertinia Jouss., 1. c., pi. 10, f. 6, 8). 



Shell calcareous, limpet-like, oval, with thin edges and subcentral 

 summit inclined toward the shorter end of shell, which is nail- 

 shaped, with muscular impression within. Soft part unknown. 

 (Jouss.'). 



This shell must have much resemblance to a worn Helcioniscus 

 toreuma or nigrolineatus (see MANUAL, vol. xiii, p. 135), with the 

 periphery broken down to the muscle impression, and with the out- 

 side worn. Can the learned Doctor have been deceived ? 



B. bertinia Jouss. (PI. 71, figs. 68, 69). Shell ovate-oblong, 

 patelliform, convex outside, the vertex excentric, bent toward the 

 anterior side ; white and nail-shaped in front, with an impressed 

 muscle scar ; the anterior surface, as well as the lateral notches, 

 smooth and shining, colored yellowish-brown toward the summit, 

 nacreous white toward the borders, as if the anterior part had been 

 buried in the tissues of the animal nearly to the apex, while behind 

 it was joined at the edges only. Posteriorly rounded and smooth, 

 with fine lamellose growth-lines toward the summit, a little swollen 

 and shining; its color of a yellow-orange white, is masked toward 

 the summit by a wide spot of deep brown, which emits rays nearly 

 to the periphery of the same color, more or less long, and quite 

 widely spaced. The interior, which is concave, smooth, shining 



