28 BUL,1,ETIN 34 60 



pitrpuratus Conrad, Amer. Marine Conch., p. lo, pi. 2, f. 



I, 1 83 1. Not of Lamarck. 



dislocatus Holmes, Post-Plio. Fos. S. C, p. 12, pi. 2, f. 12, 

 1858 ; Hilgard, House of Rep., E-x. Doc. i, pt. 2, p. 888, 

 1S78. 



irradians var. dislocatus Dall, Bull. 37, U. S. Nat. Mus., p. 

 34, 1889 ; Single}^ Fourth Ann. Rept. Texas Geol. Surv , 

 324, 1S92. 



gibbus var. dislocatus Dall, Trans. Wagiier Inst. Sci., 3, pt. 

 4, p. 746, 1898 ; Idem, pt. 6, p. 1615, 1903. 

 Remarks : Linnaeus' description of O. gibba was based on the 

 drawing of a Jamaican Pecten by Browne (Civil and Nat. 



Hist. Jamaica, p. 41, pi. 40, fig. 10, 1756J. According to 



Dr. Dall, this is identical with dislocatus Say. 

 Distribution. — Hatteras to Brazil and west coast of Africa. 

 Miocene to Recent. Gulf coast. — Recent : Cedar Keys, 

 Fla ; Matagorda, Corpus Christi, Texas. Pleistocene : 

 Orient and North Creek, Fla. ; Nev/ Orleans well of 1856 

 at 235, 480, 546 feet ; Lake Borgne borings (?); Knapp's 

 wells, Terrebonne Parish No. i at 2000-2150, 2250-2450, 

 No. 3 at 570-700, 1150-1200, 1200-1300, 1330-1375, 1400-1440, 

 1443-1470, 1500-1525 feet. 



(Plagioctenium) gibbus irradians Lamarck 



Pecten iri'adians Lamarck, An. s. Vert., 6, p. 173, 1819. 

 conce7itricus So-y , Jour. Acad. Nat. Sci. Phila., p. 259, 1822. 

 irradia7is Ooxxld, Binney's Ed. Invert. Mass., p. 199, fig. 496, 

 1870 ; Dall, Bull. 37, U. S. Nat. Mus., p. 34, pi. 53, fig. 



II, 1889 ; Singley, Fourth Ann. Rept., Geol. Surv. Texas, 

 p. 324, 1892. 



gibbus V2ir. irradians Dall, Trans. Wagner Inst. Sci., vol. 3, 

 pt. 4, p. 748, 1898 ; Vanatta, Proc. Acad. Nat. Sci. Phila., 

 vol. 55, p. 756, 1903. 

 Distribution. — New Jersey to Texas. Pleistocene to Recent. 

 Gulf coast. — Recent : Tampa, Florida ; Horn Island 

 Miss. ; Chandeleurs, La. ; Corpus Christi, Galveston 

 Texas. Pleistocene: North Creek, Manatee Co., Fla. ; 



