PACIFIC COAST SPECIES. 



107 



ital system of tbe Mendocino County specimens. The question of spe- 

 cific identity is also difficult in living specimens. The digestive system 

 of the same form is figured on PI. XIII, Fig. 3, of Ann. N. Y. Lye, X. 

 It quite resembles that of Avion hortensis as figured byLeidy in Vol. I. 

 It is much more simple than that of Ariolimax. The salivary glands 

 are very broad and very aborescent, and form a broad collar around 

 the oesophagus and commencement of the stomach. The last-named 

 organ is very broad. This variety has been received by me from Dr. 

 Cooper under the name of Avion Andevsoni. If it really be that spe- 

 cies, it may retain its specific name, but must be considered still a true 

 Prophysaon. Cooper's description of A. Andersoni does not agree with 

 this slug, especially as to the presence of a caudal mucus pore. 



B. notabilis, partially extended, 

 enlarged. 



Fig. 72. 



BINNEYA, J. G. Cooper. 



Animal heliciform, obtuse before, rapidly acuminated behind; man- 

 tle subcentral, extending anteriorly beyond fig.ti. 

 the shell ; a distinct locomotive disk ; no 

 caudal mucus pore; respiratory orifice poste- 

 rior, on the right edge of the mantle; anal 

 orifice contiguous to last; genital orifice be- 

 hind the right eye-peduncle. 



Shell entirely external, ear-shaped, nearly flat, about one-third as 

 long as the animal, which it does not half cover when retracted. Spire 

 flattened, forming two horizontal volutions, last 

 whorl enormously expanded and slightly arched. 

 Columella distinct, entire, hiding the interior of 

 the convolutions; peristome simple, acute. In 

 estivation the part of the animal excluded from 

 the shell is protected by a thick, white, parch- ^^*^ ^^p'p^'^s'^ ''' ''"^''*'"°- 

 ment-like epiphragm. 



A genus of the Mexican fauna, whence it has been introduced on 

 Guadelupe Island off the west coast of Mexico, and Santa Barbara 

 Island, coast of California. ftg 73. 



The jaw is thick, slightly arcuate, ends 

 blunt; anterior surface with six well-devel- 

 oped ribs, denticulating either margin, situ- 

 ated on the central third of the jaw, and as 

 many subobsolete ribs on each outer third; no median projection. 

 (Fig. 73.) 



Animal of Binneya notabilis 



Jaw of B. notabilis. 



