176 Jaw and Lingual Dentition of Pulmonata. 



Laterals like the centrals, but unsymnaetrical : the cutting point becomes 

 longer as they pass off laterally, and at the 12th tooth it commences to be 

 bluntly trifid. The marginals are peculiar ; their base of attachment is 

 subquadrate with a single broad cusp, bearing a very broad, oblique, ex- 

 panding, trifid cutting point ; the outer division very small, pointed ; the 

 median longer, very broad, squarely truncated ; the inner one about half 

 the size of the median, recurved and sharply pointed. 



In pi. xiv, fig. A, I have represented the dentition of that portion of 

 the lingual membrane where the cutting points are least developed. PI. 

 xv, fig. A, represents that portion where they are most so. It must 

 always be borne in mind that such differences of development exist in all 

 membranes. 



The dentition of this species is peculiar, resembling that common in 

 Orthalicus rather than the type usual in Helix. 



Helix leporina, Gould (Polygyra). 

 Texas. Mr. A. G. Wetherby. 



Jaw as usual in the subgenus (see Phila. Proc. 1875, 201), with 12 

 ribs. 



Lingual membrane as usual in the subgenus (see id.). Teeth 18 - 1 - 18, 

 with 8 laterals (pi. xviii, fig. B). The loth tooth figured is from another 

 portion of the membrane from that furnishing the 13th. The extreme 

 right hand figure of my plate represents a deformed first lateral tooth. 



Helix auriculata, Say (Polygyra). 



St. Augustine, Florida, under the ruins of the sugar house 

 chimneys at Hanson's deserted plantation. 



Having collected specimens of undoubted identity at Mr. Say's original 

 locality, I have compared the genitalia with those figured by Leidy (Terr. 

 Moll. U. S., I. pi. ix) and find them to agree. This is important, as the 

 name " auriculata" was used in that work to cover several species. 



I have also given (pi. xviii, fig. E) a better figure of the dentition 

 than in Proc. Phila. Ac. Nat. Sc, 1875, pi. viii, fig. 12. There are 2G- 1 -26 

 teeth. The inner cutting point of the 13th tooth is bifid, so that there are 

 12 laterals. 



Jaw with 10 ribs. 



Helix uvulifera, Shuttl. (Polygyra). 

 Genitalia as in H. auriculata. 



Helix septemvolva, Say (Polygyra). 



St. Augustine, Florida. 



Plate xii, fig. 6, represents the genital system of the large form of this 



