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 TERTIARY FAUNA OK FLORIDA OJ 



I'fitfii clail'wiit-nsis Harris, Rep. C.eul. Surv. Ark., 1892, ii., p. 145 ; Proc. Acacl. Nat. 



Sci. 1'hila. for 1896, p. 470 (name only), pi. xviii., tigs, i, 2, 1896. 

 /'st-iiitaiinisiiiiii clailionu-nst: Harris, Hull. Pal., 9, p. 43, pi. 7, fig. I, 1897. 



Chickasawan (or Lignitic) Eocene of Ilachetigbee Bluff, Alabama, of the 

 Wahtubbco hills, Clarke County, Mississippi, and at Enterprise, Mississippi; 

 Claibornian of St. Maurice, Louisiana, and of the bluff at Claiborne, Alabama; 

 Jacksonian (green marl bed), Jackson, Mississippi, and Clarke County, Missis- 

 sippi ; Burns and L. C. Johnson. 



The specimen described as scintillatus by Conrad is very young and more 

 oval, and with the discrepancies of the ears less marked, than in adult speci- 

 mens such as were figured by Harris, who also suggest* the relationship, which 

 a large series of different ages enables me to confirm. The distinctions 

 between this species and P. calvatus are mentioned in the remarks under the 

 head of that species. The Camptonectes striation is more marked in the 

 young, but rather variable as between individuals. This species is the type of 

 Conrad's subgenus Ebumeopecten, which he afterwards regarded as a synonyme 

 of Camptonectes. P. clailwrncnsis, as such, has never received a formal diag- 

 nosis, though it has been referred to and figured several times on the strength 

 of Conrad's manuscript label in the Academy's collection. 



Pecten (Pseudamusium) frontalis Dall. 

 l\; ti-n AVj,v/-.v/ Clark, Bull. I'. S. Cicol. Surv., No. 141, p. 85, pi. 34, figs. 2 a, b, c, 1896; 



Johns Hopkins Un. Circ., xv., p. 5, 1895. 

 Not /'. AVi/vrj-/ Conrad, Journ. Acacl. Nat. Sci. Phila. , vii., p. 151, 1834. 



Eocene of Potomac Creek, Front Royal, Virginia, Clark ; Jacksonian of 

 Garland's Creek, Clarke County, near Shubuta, Mississippi, Burns. 



The specimen described by Clark is young, only eighteen millimetres in 

 height, but Burns obtained specimens twenty-nine millimetres high by twenty- 

 eight wide in Mississippi. The radial sculpture is obsolete near the centre of 

 the disk and on the beaks, but well marked near the margin. There are about 

 seventy small, low, flattened riblets separated by narrower grooves. The ears 

 are small and the posterior ear smaller and obliquely truncate. The shell is 

 moderately convex and recalls /'. choctdrcusis Aldr., but with much feebler 

 sculpture. 



Pecten (Pseudamusium) cerinus Conrad. 

 /'</< ft->iniis Conr., Am. Journ. Conch., v., p. 39, pi. 2, fig. 2, 1869. 



Miocene of Charles County, Maryland, Cope; Ashley River phosphate 

 rock, South Carolina, Dall. 



