CHIEFLY OF THE UNITED STATES. 117 



Paludina umbilicata, pi. 22, fig. 8. 



Testa carinata, obtuse conoidoa, viridi-brunnea, subtenui, umbilicata, nitida ; spira obtusa, haLylonica ; 

 suturis linearlbus ; anfractibus senis, carinatis, superne planulatis, minute et transverse striatis; aper- 

 tura subi-otundata, intus albida; umbilico spiraliter carinato ; columella incurvata. 



Shell carinate, obtusely conical, greenish brown, rather thin, umbilicate, shining; 

 spire obtuse, tower shaped; sutures linear; whorls six, carinate, flattened above, 

 transversely and minutely striate ; aperture nearly round, whitish within ; umbilicus 

 spirally carinate ; columella incurved. 



Proc. Acad. Nat. Sei., 1856, p. 109. 



Hah. — Takrong River, Siara, Mr. Haines. 



My cabinet and cabinet of Mr. Haines. 

 Diam. -45, Length -67 inch. 



Remarks. — A single specimen only of this very j:em ark able species was among the 

 shells received by Mr. Haines from Siam. It is from Takrong Eiver^ a tributary to 

 the Cambodia River. This specimen has three distinct revolving carina nearly equi- 

 . distant. The lower one is the most distinct, and curves spirally round the umbilicus, 

 forming the outer portion of it. The middle one marks the junction of the whorl, and 

 the superior one forms the outside border of the flattened portion of the whorls, which 

 gives the shell somewhat the appearance of the tower of Babylon. Some of the stride 

 are minutely dotted.' I have no knowledge of any Paludina that has so marked a 

 carinate border to the umbilical region. The operculum is of a light brown color and 

 semitransparent, with the polar point rather nearer the columellar border than usual. 



Paludina Ingallsiana. PI. 22, fig. 9. 



Testa carinata, obtuse conoidea, tenebroso-viridi, tenui, umbilicata, nitida ; spira obtusa ; suturis linearibus ; 

 anfractibus senis, subplanulatis, miuutissime et transverse striatis ; apertura rotundato-elliptica, inferne 

 subangulata, intus ciBruleo-alba. 



Shell carinate, obtusely conical, dark green, thin, umbilicate, shining ; spire obtuse ; 

 sutures linear ; whorls six, rather flattened, finely and transversely striate ; aperture 

 rotundo-elliptical, subangular below, within bluish white. 

 Proc. Acad. Nat. Sci., 1856, p. 110. 



mS.-Siam, T. R. Ingalls, M. D. 



My cabinet and cabinet of Dr. Ingalls. 

 Diam. SI, •• Length •52 inch. 



Remarks. — This species is closell)^ allied to umhillcata, herein described, but I think, 

 although I have but a single specimen before me, that it should he separated. It has 

 not that well characterized flattening of the superior portion of the whorl so renuirka- 



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