PLANORBIS. 



13T 



umbilicated below ; whirls five, obtusely carinated above, below acutely 



so ; aperture white, thick, strongly coustricted ; 



Fig. 226. within are six teeth. Fig. 227. 



Cotoma Creek, Montgomery Co., Ala. (^Lea.) 



Planorhis wheatleyi, Lea, Pr. Phila. Acad. Nat. 



Sc. 1858, P.-41. mgmentina 



I have specimens received from Florida, 

 which, on comparison with Mr. Lea's type, are evi- 

 dently the same. It is a well-marked species, nearly 

 allied to Seg. armigera, but distinguished by its earination, &c., 

 and by the body whirl being continued beyond the thickened, 

 heavy lip, making it " duplicatim continuatum," like that of Heli' 

 cina tropica. The shell figured w'as given me by Mr. Lea. 



Fig. 228. 



Segmentina 

 armigera. 



Fig. 229. 



(^ 



Segmentina 

 armigera. 



Segmentina armigera, Say. — Shell dextral, brownish horn- 

 color, wrinkles obsolete ; spire perfectly regular, slightly concave; suture 

 well impressed ; umbilicus profound, exhibiting the volutions ; whirls four, 

 longer than wide, obtusely carinated above, carina 

 obsolete near the aperture, a carina beneath con- 

 tinued to the aperture ; aperture longitudinally 

 subovate, oblique ; labrum blackish on the edge ; 

 throat armed with five teeth, placed two upon the 

 pillar side, of which one is large, prominent, per- 

 pendicular, lamelliform, oblique, and rounded abruptly at 

 each extremity ; near the anterior tip is a small prominent 

 conic acute one ; on the side of the labrum is a prominent lamelliform 

 tooth near the base, and two slightly elevated, oblique, lamelliform ones 

 above. Length | of an inch nearly. 

 Inhabits Upper Missouri. 



Remarkable by the teeth, but these are only discoverable by the micro- 

 scopical examination of the mouth, and they are situated far within it. 

 (Say.) 

 Planorhis armigerus, Say, Jour. Acad. Nat. Sc. II, 164 (1818) r Binkey's ed. 

 p. 63.— Haldeman, Mon. 30, pi. iv, f. 11-13 (1844).— Gould, Invert. 

 205, f. 138 (1841).— Adams, Shells of Vt. 155 (1842).— DeKay, N. Y. 

 Moll. 62, pi. iv, f. 64 a, b, c (1843).— Mes. Gkay, Fig. Moll. An. 

 cccx, f. 2.— Anony. Can. Nat; II, 205, fig. (1857). 

 Segmentina armigera, H. & A. Ada.ms, Gen. Eec. Moll. II, 264, pi. Ixxxiv^ 



f. 4. 

 Planorbella armigera, CxiEXU, Man. de Conch. II, 283, f. 3570. 



