32 THE NAUTILUS. 



Obsoletely striate, V. sincera (Anticosti). V. hwisii helicoidea. 



Thread-striate, V. sincera. V. hwisii (var. ?) 



Ribbed-striate, V. sincera nylanderi. V. hwisii (typical ?) 



In view of the recognized variability of all these forms, the in- 

 ference to be drawn would seem inevitable. 



Explanation of Plate I. 

 All the figures are drawn on the same scale (X 5) except 4, 5 and 

 6 which were drawn by Miss Helen Winchester, and these are sub- 

 stantially the same. 



Fig. 1-3. V. sincera, High Island Harbor, Lake Michigan. 

 " 4-6. V. sincera, Anticosti. 



» 7—9. V. sincera nylanderi, Portage Lake, Aroostook Co., Me. 

 " 9. V. sincera nylanderi, Isle Royale, Mich. 

 " 10-11. V. sincera daniehi, Cannon Lake, Rice Co., Minn. 

 " 12-13. V. hwisii, Traverse City, Mich. 

 " 14. V. bicarinata, Philadelphia, Pa. 



" 15-16. V. bicarinata perdepressa, Lake Mich., Michigan 

 City, Ind. 



HELIX JEJUNA SAY TRANSFERRED TO PRATICOLELLA. 



BY HENRY A. PILSBRY. 



Recently I received from Mr. George H. Clapp some living ex- 

 amples of this small snail, with a request that they be examined 

 anatomically to determine the generic position of the form, which 

 has of recent years been grouped with the small Polygyras of the 

 " Mesodon " type. 



The snails were collected at Lemon City, Dade Co., Florida, by 

 Mr. Chas. T. Simpson. Externally the soft parts do not differ from 

 Polygyra and many other genera of Helices. 



The terminal ducts of the genitalia are shown in Fig. 1. The 

 penis bears the retractor and vas deferens at its apex. Near the 

 base a very large gland or " appendix " is inserted (a in the figure). 

 This seems to be a nearly solid but soft and readily broken gland. 

 The vagina is more than half as long as the penis. The spermatheca 



