MUSEUM OF COMPARATIVE ZOOLOGY. 151 



margin of the foot and caudal mucus-pore, over which is a hump-like process : 

 no distinct locomotive disk: external respiratory and anal orifices at the central 

 right margin of the mantle : orifice of combined genital system near the right 

 eye-peduncle. 



Shell-plate horny, small, unguiform, longer than wide, with posterior nucleus 

 and concentric lines of growth, exposed in part. 



Jaw ribbed. 



Lingual membrane with tricuspid central teeth, bicuspid laterals, and quad- 

 rate marginals. 



Coast of Oregon. 



The swollen central portion of the animal seems the first approach to a tur- 

 binate mass of viscera, separated from the foot. 



This emended generic description is drawn from larger specimens (40 mm. 

 contracted in alcohol) collected at Portland, Oregon, by Mr. II. Hemphill. 

 Found also at Tacoina, Puget Sound, and Olympia, Washington Territory, by 

 the same collector. 



Polygyra auriculata, SAY. (p. 263.) 

 Cedar Keys : St. George's Island, Florida. 



Polygyra Texasiana, MORICAND. (p. 270.) 

 Fort Gibson, Indian Territory. 



Polygyra Dorfeuilliana, LEA. (p. 278.) 



Fort Gibson, Cherokee Nation, Indian Territory : Alexandria, Louisana. 

 Wetherby suggests the specific name of Sampsoni for the variety described 

 in Vol. V. 



Polygyra pustuloides, BLAND, (p. 287.) 

 Lookout Mountain, Tennessee. 



Polygyra leporina, GOULD, (p. 288.) 

 Fort Gibson, Indian Territoiy. 



Polygyra Harfordiana, J. G. COOPER, (p. 309.) 



Fig. 203 is said by Dr. Cooper not to represent his species, but rather the 

 Salmon River small form of Mesodon dcvia van Mnllani. I have, therefore, 

 here given a figure of Dr. Cooper's original type of 

 D. Harfordiana preserved at the Academy of Natural 

 Sciences at Philadelphia. The species from this seems 

 more nearly allied to Polyyym than to Trwdnpsis. 



