68 Bulletin 9 360 



and seem to have no relationship to the inferior, operculate, rad- 

 ially folded and grooved left valve of onisciis. 



A very minute specimen from Gregg's landing, about as large 

 as a pin head shows, when highly magnified, a smooth, rotund 

 left valve, and a similar but larger right valve, strongly striate 

 concentrically, to the ver^^ beak. No radii are present. 



Type. — Aldrich's colledlion. 



Localities (lyignitic). — Alabama: Woods Bluff; near mouth of 

 Bashi creek; Gregg's Landing; 4 miles above Ham- 

 ilton Bluff; Hatchetigbee; Ozark. 



Specimens figured. — -Hatchetigbee; Paleont. Museum, Cornell 

 University. 



Corbula alabamiensis var. pi i-^, fio^. 14, a. 



Syn. C. engonata Aid.. Bull, i, Geol, Surv. Ala., p. 58, 1SS6. 



This variety is by no means so large nor so inflated as alabam- 

 iensis, yet some specimens seem to indicate a transitional stage so 

 far as form is concerned. From Corbula engonata this is distin- 

 guished by its more compressed form, smaller concentric lines 

 and more rectilinear base. 



Locality. — Alabama: Gregg's Landing. 



Specimen figured. — Paleont. Museum, Cornell University. 



Corbula alabamiensis. 



Syn. C. nasiita Con. (preoccupied) Foss. Sh., Tert. Form, p. 38, 1833; 

 pi. 19, fig. 4 of Harris' republication. 



C. alabamiefisis Lea, Cont. to Geol., p. 45, pi. i, fig. 12, 1S33. 



Corbula nasuta Aid., Bull, i, Geol. Surv. Ala., p. 58, 1886. 



Lea's original description.— "Shell inflated, triangular-ovate, 

 angular behind, transversely and finely stiate, inequilateral, very 

 inequivalve, anterior part the larger ; beaks incurved and rather 

 pointed ; tooth of the right valve large, pointed and fitting under 

 the beak of the left valve ; posterior basal margin straight or 

 slightly emarginate; the two great cicatrices distin(51:ly impressed; 

 cavity of the valves deep. Diameter 7-2oths. Length .4. Breadth 

 .7 of inch." Claiborne, Ala. 



The specimens here included under typical alabamie7isis , are 

 much smaller than most specimens from Claiborne. There seems, 

 however, to be little doubt of their identity. 



