MELANTHO. 



SowERBY, Gen. of Shells, f. 2.— Chen0, Man. de Concfl. I. 810, fig. 



2206 (Melantho) ; lllust. Conch, pi. i. f. 14-15 ; Lee. Elem. d'Hist. 



Nat. p. 171, f. 559, 560(1847).— Philippi, Conch. Ill, 3, pi. i, f. 0(1848). 

 Ampullaria crassa, Deshayes, Encycl. Meth. II, 32 (1830). 

 faludina crassa, Say of Deshayes 1. c. 

 Paludina decisa (part). Reeve, Con. Icon. f. 45 b. 

 Faludina regularis, Lea, Tr. Amer. Phil. Soc. IX, 13 (1844) ; Obs. IV, 



13; Proc. II, 34 (1841) ; Arch. f. Nat. II, 130 (1843).— Reeve, Con. 



Icon. pi. yi, f. 69 (1863). 



I have received specimens from Ohio, Indiana, Illinois, Michi- 

 gan near Lake Superior, Tennessee, and Alabama. 



There are microscopic revolving lines upon the whirls of many 

 specimens, and the callosity at the superior angle of the aperture 

 is sometimes developed sufficiently to make quite a fissure be- 

 tween it and the lip, as in Litliasia. This is an important 

 feature which serves to distinguish it from the allied species, as 

 does also the highly developed curvature of the peristome (sec 

 Fig. VI), the extreme thickness of the shell, the heavy, deeply 

 entering callus on the parietal wall of the aper- 

 ture, the shorter spire, and more globose outline 

 of the shell. It appears to me a distinct species, 

 readily distinguished from M. decisa 

 and 31. Integra, in early stages of 

 growth as well as when mature — the 

 young shells being very much more 

 globose than the young of those 

 species. 



From the Coosa River, in Alabama, 

 Dr. Showalter has sent numerous spe- 

 cimens of this species, which were formerly noticed by Prof. Halde- 

 man as var. a. They are extr^ely solid. 

 have the callosity of the 

 upper portion of the aper- 

 ture highly developed, are 

 constantly truncated in the 

 early as well as later stages 

 of growth, and when ma- 

 ture are very much eroded 

 even upon the body whirl, 

 They have the usual fea- 



Melantho ponderosa. turCS of M. J^OuderOSa Mdnntho ponderosa. 



Fig. 73. 



Melantho ponde- 

 rosa, young. 



Fig. 74. 



