156 PROCEEDINGS OF THE ACADEMY OF 



tSuocinea Hawkinsi, Bid. tSuccinea Oregonensis, Lea. 



trusticana, Gld. effusa, Shuttl. 



Nuttalliana, Lea. tSalleana, Pfr. 



YERONICELLID.E. 



Veronicella Floridana, Binn. IVeronicella olivacea, Stearns. 



A. Jaw absent. 

 Family OLE A C IN I D.E. 



Genus GLANDINA, Schum. 



Lingual membrane narrow, with chevron-shaped rows of uni- 

 form, aculeate, separated teeth ; central tooth with a long, slender, 



Fig. 1. Fig. 2. 



Lingual membrane of O. truncata. Lingual dentition of Glandina truncata. 



straight base of attachment, with incurved sides, and with inferior 

 lateral slightly expanded angles, and with the upper margin re- 

 flected and extended into a long, slender, acutely pointed cusp. 

 There are no lateral teeth, the balance of the membrane being 

 composed of marginal teeth of the pure aculeate form. 



Each row of teeth on either side of the median line curves first 

 backward, with the teetli rapidly increasing in size as they pass 

 outwards, and then forwards as the teeth gradually again become 

 smaller ; giving an irregularly crescentic shape to the half row of 

 teeth. This is shown particularly in Gl. Albersi and G. rosea, 

 less so in GL truncata. The central tooth was overlooked by 

 Wyman, Leidy, and other of the earlier investigators. It has 



