i65 Midway Stage 51 



CUCULL^A. 

 Cuculltza macrodonta, PI- 3. %§. 10, a. 



Syn. C. macrodonta Whitf., Am. Jr. Conch., vol. i, 1865, p. 



267, pi. 27, fig. 17. 

 Whitfield' s original description.— '' ^\^.^Vl of medium size, sub- 

 rhomboidal in outline, broad heart-shaped in profile; hinge Ime 

 nearly as long as the greatest length of the shell; hmge area 

 broad, corrugated; valves deep; beaks distant, slightly incurved; 

 surface marked by from forty-five to fifty low, radiatmg ribs, 

 which are finely corrugated by concentric lines; ribs indistinct on 

 the posterior part; a rather deep, narrow sulcus extends from the 

 beak to the posterior basal angle, leaving a prominent umbonal 

 ridge; hinge line with sixteen teeth, the right valve having four 

 at each extremity parallel to it; muscular scars sub-quadrangular, 

 the posterior much the largest; muscular ridges faint or obsolete; 

 pallial line crenulate; inner margin of shell smooth. 



"This species is remarkable for the very transverse lateral 

 teeth, a feature not often noticed in fossil species of the genus. 

 "Z!^m/z/y.— Nine miles below Prairie Bluff, Alabama." 

 When the two valves of this species are found together, the 

 right is somewhat smaller, and shuts into the left along the basal 

 margin. Whitfield apparently had but one valve (right), and 

 hence his description is more applicable to the following species 

 than it is to this. The surface markings of the two valves are 

 shown in our figures; that of the right is constant while that of 

 the left is subject to extreme variations. Some specimens, especi- 

 ally those found along the Tombigbee river, show but three or 

 four ribs of the stronger series on the left valve; others show 

 less pronounced difference in sculpturing between the two valves. 

 Localities.— "Xl^^hs,: Brazos river, near Falls-Milam Co. line; 

 Webberville, Colorado river. 

 Alabama: Tombigbee river. Black Bluff and below 

 as far as Naheola; ? i mi. north of Midway; Mat- 

 thews' Landing; i mi. N. of Allenton; i mi. W. 

 of Oak Hill; >^ mi. W. of Graveyard hill. 



Type. — Hall's collection. 

 Cucullcea saffordi, PL 3> %• n; pl- 4. figs, i, 2. 



Syn. Area saffordi Gabb, Jr. Ac. Nat. Sci. Phila., vol. iv, 

 i860, p. 397, pi. 68, fig. 38, non 37 as in text. 

 Cucullcea macrodonta Har.. Geol. Surv. Ark., vol. n, 



1892, p. 41. 

 C. transversa Aid., Geol. Surv. Ala., 1894, p. 242. 



