PECTEN. 145 



i^aw%— PECTINID^,! Lamard-. 



Genus — Pecten, Midler, 177G. 



(' Prodr. Zool. Dan.,' p. 248.) 



Sub-gemis — Synoyclonema, F. B. Meek, 1864. 



(' Clieclc List of Invert. Poss. N. America, Cret. and Jur.,' Smithson, Misc. Coll. 177. pp. 7, 31.) 



Syncyclonema should probably be united with Entolium, as has been suggested 

 by Philippi, since in the former the concentric ornamentation of the right valve is 

 sometimes incompletely developed, and the ears have, in some cases, a more or less 

 well-marked dorsal prolongation ; on the other hand, in some forms of Entolium the 

 dorsal prolongation of the ears is insignificant. Syncyclonema is the earlier of the 

 two names. The type of Entolium^ is Pecten demissus, Phillips ; this has also been 

 taken l)y Verrill ^ as the type of Frotanmsium. 



Pecten (Syncyglonejia) oubiculaeis, Soiverly, 1817. Plate XXVII; and Text- 

 fig. 1. 



1817. Pecten orbicularis, /. Sotverly. Min. Conch., vol. ii, p. 193, pi. clxxxvi. 

 1819. — — Lamarck. Anim. sans Vert., vol. vi, pt. 1, p. 182. 



1822. — LAMiNOsus, G. Manfell. Foss. S. Downs, p. 128, pi. xxvi, figs. 8, 22. 

 1825. — OEBicuLAEis, Defronce. Diet. Sci. nat., vol. xxxviii, p. 252. 



^ Recent accounts of the classification of the Pectinidse have been given by — A. E. Verrill, " A 

 Study of the Pectinidse, with a Revision of the Genera and Sub-genera," ' Trans. Connecticut Acad.,' 

 vol. x (1897), p. 41. F. Sacco, " Molluschi dei Terreni Terziarii del Piemonte e della Liguria ; " pt. 

 24, " Pectinidaj," 1897. W. H. Dall, " Tertiary Fauna of Florida," ' Trans. Wagner Free Inst, of 

 Philadelphia,' vol. iii, pt. 4 (1898), pp. 689 — 758. E. Philippi, " Beitriige zur Morphologic und 

 Phylogenie der Lamellibranchier : " (1) " Hinnites und Velopecten," ' Zeitschr. der deutsch. geol. 

 Gesellsch.; vol. 1 (1898), p. 597; (2) "Zur Stammesgeschichte der Pectinideu," ibid., vol. Iii (1900), 

 p. 64. A. Locard, " Faune Malacologique Fran9aise," xi, " Monographie des Espcces appartenant au 

 Genre Pecten," '^nn. Soc. Linn, de Lyon,' vol. xxxiv (1888), p. 133. C. Deperet and F. Roman, 

 "Monographie des Pectinides neogcnes de I'Europe et des regions voisines," 'Mem. Soc. gi'ol. de 

 France (Paleont.),' vol. x, pt. 1 (1902). 



2 Meeli, " Geol. Survey of California," ' Geology,' vol. i. Appendix B (1865), pp. 478, 479. 



•' ' Trans. Connect. Acad.,' vol. x (1897), p. 71. 



]9 



