438 Itemarks on Certain Species 



Helix obstricia 8ay. 



SYNONYMY. 



Helix obstrida Say Jour. Acad. JSTat, Sci. Phila., II., 154, 1821. 



jpalliata Say var. a. Jour. Acad., 1. c, 152. 



CaroUnensis Lea Trans. Amer. Phil. Soc. N. S., lY., 



108, pi. XV., figs. 33, a, b, c, 1831. 

 Caracolla helicoides Lea Trans Amer. Phil. Soc, 1. c, 109 



pi. XV., figs. 34, a, b, c. 

 'Kq\\x palliata Binney Terr. Moll. II., 136, var. pi. XV., 1851. 



var. LI. CaroUnensis W. G. Binney. Terr. 



Moll. IV., 57, 1859. 

 ^ From the dates at Avhich this species and its varieties were 

 described, the most distinctly carinated form must be treated 

 as the type, although the nature of the variations is the same 

 as in LL. palliata. 



H. ohstr'ida Say {H. helicoides Lea) differs from H. palliata 

 in the following particulars ; the epidermis is free from " tuber- 

 culous prominences," but has raised spiral lines between the 

 costse on the upper and lower surfaces of the shell. It has ele- 

 vated, rigid, distant costse, the whorls are subexserted and 

 acutely carinated, the carina of the upper whorls compressed, 

 and overlapping the sutures as in LI. Cumberlandiayia Lea. 

 The umbilicus, as in the most carinated form of B. palliata, is 

 not always entirely covered by the reflected lip. 



The typical form varies in color from pale to dark brown, 

 and also in size and elevation, as the following measurements 

 will show : 



Diam. maj. 25, min. 22, Alt. 10 mi41. (5i whorls). Cab. W. 



G. Binney, Lea ! 

 " " 23 " 20 " ^ " (5 whorls). Bersh. Spr., 



Tenn., Elliott ! My Cab. 

 « " 20 " lU " 8 " (5 whorls). Indiana, Dr. 



Ingalls ! My Cab. 



