1890.] NATURAL SCIENCES OF PHILADELPHIA. 179 



For the loan of type specimens and material sincere thanks are 

 tendered: Prof. G. C. Broadhead, State University of Missouri ; 

 Dr. J. S. Newberry, School of Mines, Columbia College, New York 

 City ; Mr. Charles D. Walcott, U. S. Geological Survey, Washington, 

 D. C. ; Dr. Alexander Winchell, University of Michigan, Ann 

 Arbor; Mr. E. O. Ulrich, Newport, Ky. ; and especially Messrs. 

 Oharles Wachmuth and Frank Springer. 



IV. Spurious and Doubtful Species of Carbonic Capuli. 



Platyceras bivolve White & Whitfield. (Proc. Boston Soc. Nat. 

 Hist., vol. VIII, p. 302. 1862.) A careful examination of the type 

 specimen appears to indicate that this form is a true Platystoma and 

 it has accordingly been transferred^ to that genus. Though somewhat 

 resembling the young specimens of Platyceras ventricosuin Conrad, 

 as remarked by White and Whitfield, it differs very essentially from 

 that form. The spire is much more elevated, being on a level or 

 even above the surface of the body whorl ; while the inner lip is 

 much thickened, reflexed and anchylosed to the spire. Platystoma 

 bivolve (W. & W.) has almost an exact counterpart among some 

 forms of the upper Siluric species Platystoma niagarense Hall, from 

 the Waldron (Indiana) shales. 



Platyceras cajyax K. (Proc. Am. Phil. Soc. 1888, p. 241.) Proba- 

 bly synonymous with C. equilateralis (Hall). 



Platyceras capulus Hall. (Geol. Sur. Iowa, vol. I, pt. ii, Supp., p. 

 91.1859.) If recent identifications have been correct this species 

 does not belong to the genus Capulus. 



Platyceras extinctor Meek & Worthen. (Proc. Acad. Nat. Sci., 

 Phila., p. 266, 1866.) Never formally proposed. It is evidently 

 only an elongated variety of Capulus infundibulum (M. & W.). 



Platyceras Icevlgatum Meek & Worthen. (Proc. Acad. Nat. Sci., 

 Phila., 1866, p. 263.) Synonym of Capulus ovalis (Stevens). The 

 name was preoccupied by McCoy. 



Platyceras nebrascense Meek. (U. S. Geol. Sur. Nebraska, 1872, 

 p. 227.) Only a more mature individual of Capulus parvus Swallow. 



Platyceras pabulocrinus Owen. (Kept. Geol. Sur. Indiana, p. 364, 

 1862.) Proposed for a form similar to C. infundibulum (M. & 

 W.), but \vithout description. 



Platyceras reversum Hall. (Geol. Iowa, vol. I, pt. ii, Supp., p. 91, 

 1859.) Manifestly is not a Capulus. 



1 Proc. Acad. Nat. Sci., Phila., 1889, p. 293. 



