r6 BUI.I.ETIN 2 ( 68 ) 



SIGARETUS. 



Sigarefiis {Sigatiais) darkearzics Aldr, PI. i, fig". i6. 



Hitherto unfigtired: it is described in Jour. Ciu. Soc. Nat. Hist, 

 p. 83, July, 1887. 



Locality. — Choctaw Corner, Ala, 

 Horizon. — Woods' Bluff section. 



PBI/ECYPODA. 



OSTREA, 



Ostrea cr-efacea Morton. PI. 5, fig" 10. 



Locality. — Hatchetigbee Bluff and "the Rocks," Clark Co., 

 Ala., in white limestone. 



PECTEN. 



Pectcn chocfavensis , nox. sp. PI- 5> fig'- 7- 



Shell. suborbicnlar thin, depressed, finely, closely ribbed, ribs 

 showing^ through the substance of the shell, imbricated near x^ertral 

 marg-in and on the anterior slope, smaller ribs showing between on 

 the anterior slope ; ears ribbed and ribs imbricated with fine, 

 oblique reticulations between. 



Locality. — Choctaw Corner and Wood's Bluff, Ala. 

 Pecteii clarkcanus, nov. sp. PI- 5, fig'- if- 



Shell orbicular compressed ; ears nearly equal ; beaks pointed ; 

 both valves ab'Ut equal, the right one con vex the umbones more 

 slightly convex, the apex of valves smoother vers' minutely striated 

 the lower and older part strongly marked with about 48 radiating 

 ribs, strongest on the right valve, anterior ear on right valve with 

 a sinus, ears striated. 



Locality. — ^Sowilpa Cr., Ala. 



Geological horizon. L,isboa beds. 



This species combines the characters of two subgenera. The 

 ribs in some specimens are quite plain near the beaks, then be- 

 come obsolete and suddenly reappear below, where they often 

 bifurcate. Examined under a glass, the ribs appear to be smooth 

 and rounded ; on the left valve the beaks are ribbed, but on the 

 right they appear to be smooth. Young specimens are difficult 

 to distinguish from P. sciutillatus Conrad. 



MODIOLA. 



Modiola alabaniensis, nov. sp. PI. 5, fig'. 13. 



Shell strongly arcuate, surface with raised lines closely set be- 



