SUCCINEA. 



263 



Fig. 4G9. 



From Fort Simpson, on Mackenzie River, to the Gulf of 

 Mexico ; over all eastern North America. 



A larger form is also found. 



Jaw strongly arcuate, ends curved and 

 pointed ; anterior surface smooth ; concave 

 margin simple, with a well-developed, acute 

 median projection ; convex margin waving. 



Lingual membrane with 19 — 1 — 19 teeth, 

 centrals tricuspid, laterals bicuspid, uncini 

 serrated. 



Fiff. 470. 



Jaw of Succinea avara. 



Lingual dentition of Succinea avara. 



Succinea stretcbiana, Bland.— Shell globose conic, thin, pel- 

 lucid, shining, striatulate, greenish horn-colored ; spire short, rather 

 obtuse ; suture deep ; whirls three, convex, the last 

 roundly inflated ; columella arcuate, slightly thickened ; 

 receding ; aperture oblique, roundly oval ; peristome 

 simple, with the margins joined by a thiu callus. Length 

 6|, diam. 5 mill. ; aperture 5 mill. long. ♦ 



Succinea stretchiana, Bland, Ann. N. Y. Lye. VIII, 168, 

 f. 16 (1865).— Tryon, Am. Journ. Conch. II, 231, 

 pi. ii, f. 5 (1866). 



