Foreign to the United States. 225' 



genus Bulimulus. The same may be said of Gceotis lately 

 examined by us. 



AmjpJiihulima patula. — Body obtuse in front, pointed 

 behind, entirely retractile within the peristome, though usu- 

 ally greatly expanded. Mantle simple as in Succinea, Helix, 

 etc. Base of foot wrinkled transversely, without distinct 

 locomotive disk. Generative orifice? Respiratory orifice? 



Jaw slight 1}^ arcuate, low, ends attenuated: extremely thin 

 and transparent with prominent transverse striae ; divided 

 longitudinally by about forty-five delicate ^ribs into so many 

 plate-like sections of the same character as those of Cylin- 

 drella, Macroceramus and many species of Bulimidus. No 

 upper triangular median plates as in Cylindrella. Margin 

 serrated by extremities of ribs. 



The figure we have given of the jaw of Succinea? apjpen- 

 dicidata Pfr. (Ann. Lye. Nat. Hist. N. Y., X, pi. ix, fig. 2) 

 offers a correct general idea of the jaw of Amphibidima 

 patula. See also our photograph of jaw of Cylindrella rosea 

 (Am. Journ. Conch., Y, pi. xi, fig. 2) for the character of 

 the ribs and plate-like sections. 



Lingual membrane as already described and figured by us 

 from a specimen from Dominica (See Am. Journ. Conch., 

 YII, 186, pi. xvii, figs. 1-2), long and broad, composed of 

 numerous horizontally waving rows of teeth, of the form 

 usual in the Helicidoe'. Centrals subquadrate, extended at 

 basal angles, narrowing towards the centre, expanding 

 towards the upper edge, which is reflected and tricuspid, 

 extending quite to the base of the tooth ; the cusps are stout, 

 the median one bluntly pointed. The lateral teeth are of 

 the same type as the centrals, but unsymmetrical. The 

 marginals are long and narrow, rounded at base, narrowed at 

 apex, reflected and bicuspid ; cusps short, stout, and gene- 

 rally a simple modification of those of the laterals. The 

 extreme marginals iiave irregular teeth, like simple papillse. 



[Printed at the Salem Press. 



