146 Bulletin 39 318 



intermediate cord, to more delicately sculptured forms with finer 

 tuberculated cords separated by wide and finely sculptured inter- 

 spaces. 



This species occur also in the Bowden beds of Jamaica and 

 in the Gurabo formation of Santo Domingo. 



Gafiin Stage: Hill i, 2, Banana River. 



Genus PETALOCONCHUS H. B. Lea 

 Petaiocanchus sculpturatus, H. C. Lea Plate 14, figures 10, 15 



Petaloconchiis sculpUiratus H. C. Lea, 1845, Trans. Amer. Phil. Soc, 



vol. 9, p. 233, pi. 34, fig. 3, 

 Petaloconchits donitJigensis Sowerby, 1849, Quart. Journ. Geol, Soc. 



London, vol. 5, p. 51, pi. ro, fig. 8, a b c. 



Patalocoiichus sciilptuj-atus Gabb, 1875, Trans. Amer. Phil. Soc, vol, 

 25, p. 240. 



Pataloconcbiis sculpturattis Gn^'^j , 1876, Quart. Journ. Geol. Soc. Lon- 

 don, vol. 32, p. 519. 



Vermetus [Petaloconchiis) sculptitratiis Dall, 1892, Trans. Wagner 

 Free Inst. Sci. , vol. 3, pt. 2, p. 305. 



Vermetus {Petaloconchiis) pidcher 'Rose, 1906, Bol. Inst. Geol. de Mex- 

 ico, Numero 22, p. 32, pi. 3, figs. 22, 23. 



Petaloconchus doniingensis Brown and Pilsbry, 1911, Proc. Acad. Nat, 



Sci. Phila. , vol. 63, p. 359. 

 Petaloconchus doniingensis Pilsbry and Brown, 191 7, Proc. Acad. Nat, 



Sci. Phila,, vol, 69, p. 37. 

 Pctalocofichus domingensis Maury, 1917, Pull. Amer. Pal., vol., 5, p, 



292, pi, 22, fig, II, 

 Pataloconclius doniingensis Hubbard, 1920, New York Academy of 



Science, Sci. Sur. P. R., vol. 3, pt, 2, p. 139. 



The Antillean fossil was described by Sowerby as domingen- 

 sis. It has been by some writers, considered synonymous with 

 sculpturata, described a few years earlier by H. C. Lea from the 

 Chesapeake Miocene of the eastern United States, while others 

 have given domi^igensis the rank of a full species. A close com- 

 parative study of the Costa Rica fossils with several sets of typi- 



