110 THE NAUTILUS. 



This is one of the most distinct and remarkable Unios in the 

 United States. In its general structure, the hinge characters, the 

 row of dorsal cicatrices, the incipient pallial sinus, and the gaping 

 shell it shows relationship with Unio temiissimus, and its nacre is 

 something like that of this species, but the female shell is consider- 

 ably swollen in the post-basal region, and it reminds one a little of 

 a short, compressed, female Unio rectus. The posterior opening, 

 however, is its most remarkable character, commencing about mid- 

 way up the end of the shell, and extending nearly to the ends of the 

 laterals. This gap ends abruptly above, and less so below ; the 

 edges of the shell are reflected outwards, and considerably larnel- 

 lated, and in old shells the remains of former reflected apertures 

 may be seen. The opening in a fully adult shell is about one-tourth 

 of an inch wide and one and one-fourth inch in length, and is as 

 distinct as that of Schizothcerus nuttalli of the west coast of the 

 United States, and occupies about the same relative position that it 

 does in this marine bivalve. It may possibly group with Unio ten- 

 uissimus, but it is quite likely that it will have to be made the type 

 of a new group, related to that species, to the alatus and tampicoen- 

 sis groups. 



I desire to thank Mr. Chas. T. Simpson for the valuable aid given 

 in the preparation of the above description and remarks. 



NOTES ON QUEBEC PUPID.ZE AND OTHER SHELLS. 



BY A. W. HANHAM, WINNIPEG, MAN. 



My Quebec Pupidce have just been looked over and separated for 

 me by Dr. V. Sterki, to whom I am under many obligations for 

 this labor of love. As a result my list of species, as far as these 

 small things are concerned, requires some corrections and additions. 



The following are the species taken, instead of as recorded on 

 page 101, of the last volume of THE NAUTILUS : 



Pupa armifera Say. As already recorded. 



Pupa pentodon Say. As already recorded. 



Sphijradium edentulum Drap. Not uncommon ; Isle d'Orleans 

 and St. Joseph's de Levis. 



Vertigo ovata Say. As already recorded. 



