Dentition of Pulmonata. 43 



The tail of the animal is very long and pointed. There 

 is no distinct locomotive disk to the foot. 



Succinea obliqua, Say. 



A specimen from New York, received from Dr. James 

 Lewis, furnished the jaw and lingual membrane here de- 

 scribed. 



Jaw of shape usual in the genus, with the quadrate accessory plate. 

 Cutting edge with a prominent median projection. Anterior surface with 

 decided stout ribs denticulating the cutting edge; one specimen had 

 three broad and two intervening narrow ribs : another specimen has 

 seven ribs. 



Lingual membrane long and narrow. Teeth about 43-1-43. Centrals 

 subquadrate, tricuspid, the middle cusp long and stout. Laterals longer 

 than wide, bicuspid, the third, inner cusp being only rudimentary. 

 Marginals a modification of the laterals, with one long, slender inner 

 cusp, and two short, slender outer cusps. The cusps of all the teeth 

 bear sharp cutting points. 



In Terrestrial Mollusks of United States, vol. I, pi. xiii, 

 fig. 3, a jaw is figured as that of Succinea ovalis. It no 

 doubt represents rather that of the true obliqua, Say, than of 

 Succ. ovalis, Gld. not Say. The jaw of the latter is figured 

 in L. and F. W. Shells of N. A., I, p. 258. The figure of 

 genitalia given by Dr. Leidy on the plate referred to cor- 

 rectly represents that of S. obliqua. 



EXPLANATION OF THE PLATES. 



