1905.] NATURAL SCIENCES OF PHILADELPHIA. 11 



Ostrea faloata Jlorton, Jour. Acad. Nat. Sci., VI, 1 ser., 50, pi. I, f. 2, 1827. 

 Ostrea torosa Morton, Syn. Org. Rem., 52, pi. X, f. 1, 1834. 



This is an eroded fragment of a large Exogyra costata Say. 



Ostrea (Gryphaeostrea) vomer (Morton). 



Gryphcca vomer Morton, Syn. Org. Rem., 54, pi. IX, f. 5, 1834. 

 Grypliaea pitcheri Morton, Syn. Org. Rem., 55, pi. 15, f. 9, 183 1. 



Tliis is now considered a synonym of G. corrugata Say. 

 Gryphaea mutabilis Morton, Jour. Acad. Nat. Sci., VI, 81, pi. IV, f. 3, 1828. 



Dr. Dall is wrong in considering this a synonym of Ostrea compressi- 

 rostra. The specimen he refers to might be that species, but the type 

 is not; it is a broad, flattened form of G. convexa Say, which is consid- 

 ered by most authors to be the same as Lamarck's G. vesicularis. 

 Gryphaea convexa (Say). 



The specimen figured by Morton (Jour. Acad. Nat. Sci., VI, 79, pi. 4, 

 figs. 1, 2, 1828). 



Gryphaea bryanii Gabb, Proc. Acad. Nat. Sci., 1876, 321. 



The specimens figured by Whitfield (pi. 27, figs. 6-9) are not the types, 

 but probably a suite of co-types presented to the Academy by Gabb. 

 Specimens marked "type" in Gabb's handwriting I found in the 

 drawer marked "Gabb collection" above referred to. 



TRIG-ONID^. 

 Trigonia thoracica Morton, Syn. Org. Rem., 65, pi. 15, f. 13. 1831. 

 Trigonia eufalensis Gaub, Jour. Acad. Nat. Sci., IV, 2 ser., 396, pi. 68, f. 32, 1860. 



Also the specimen figured by Whitfield (pi. 14, figs. 1, 2). This is 

 only the young of T. thoracica. 



Trigonia angulioostata Gabb, Proc. Acad. Nat. Sci., 1876, p. 312. 



PECTINID^. 

 Pecten cratioula Morton, Amer. Jour. Sci., 1 ser., XXIII, 293, 1833 ; Syn. Org. Rem., 57. 



Figm-ed by Whitfield (Mon. U. S. Geol. Sur., IX, 49, pi. VII, figs. 

 17, 18). 



Pecten venustus Morton, Amer. Jour. Rci., 1 ser., XXIII, 29?, pi. 5, f. 7, 1833. 

 Pecten quinquenaria Conrad, Jour. Acad. Nat. Sci., II, 2 ser., 275, pi. 24, f. 10, 1854. 

 Pecten mississippiensis Conrad, Jour. Acad. Nat. Sci., IV, 2 sen, 283, 1860. 

 Pecten tenuitesta Gabb, Proc. Acad. Nat Sci., 1861, 327; Whitfield, Mon. U. S. Geol. Sur., IX, 

 47, pi. VII, fig.s. 5, 6. 



Pecten burlingtonensis Gabb, Jour. Acad. Nat. Sci., IV, 2 ser., 304, pi. 48, f. 26, 1860. 

 Pecten bellisculptus (Conrad). 



Camptonedes bellisculptus Conr., Amer. Jour. Conch., V, 99, pi. 9 f 11 

 1869. ' ■ ' 



Dr. Whitfield is right in uniting this with P. hurlingtonensis; further 

 study may prove that both are synonyms of P. argillensis Conr. 



