BIBLIOGRAPHIC LIST OF GENERA AND SPECIES. 1023 



POLYTROPIS Dekoninck. See Poleumite Clarke and Ruedemann. 



PONTOBDELLOPSIS Ruedemann. Genotype: P. cometa Ruedemann. 



Pontobdellopsis Ruedemann, Bull. New York State Mus., 42, 1901, p. 574. 



Pontobdellopsis cometa Ruedemann. 



Pontobdellopsis cometa Ruedemann, Bull. New York State Mus., 42, 1901, 



p. 574, pi. 1, figs. 14-18. 

 Trenton (Snake Hill) : Rural Cemetery, near Albany, New York. 



PONTOCTPRIS Sars. Genotype: P. semilata Sars. 



Pontocypris Sars, Oversigt af Norges Marine Ostracoder, 1865, p. 15. Brady, 

 Intellectual Observer, 12, London, 1867, p. 118. Ulrich, Zittel-Eastman 

 Textb. Pal., 1, 1900, p. 646. Bassler, ibid., 2d ed., 1913, p. 740. 



Pontocypris arcuata Ulrich and Bassler. 



Pontocypris arcuata Ulrich and Bassler, Maryland Geol. Surv., Low. Dev., 1913, 



p. 541, pi. 98, figs. 23-25. 



Helderbergian (Keyser): Cumberland, Maryland. 

 HolotypeG&t. No. 53288, U.S.N.M. 



Pontocypris(?) illinoisensis Ulrich. 



Pontocypris(?) illinoisensis Ulrich, Jour. Cincinnati Soc. Nat. Hist., 13, 1890, 



p. 107, pi. 10, figs. 16a-c. 

 Richmond (Maquoketa): Savannah, Illinois. 

 Holotype.Cat. No. 41333, U.S.N.M. 



Pontocypris inawl breviata Jones. 



Pontocypris mawii var. breviata Jones, Ann. Mag. Nat. Hist., 6th ser., 4, p. 269, 



pi. 15, fig. 4. Ulrich and Bassler, Maryland Geol. Surv., Low. Dev., 1913, 



p. 541, pi. 98, figs. 26-28. 

 Silurian: Gotland. 1 



Helderbergian (Keyser): Cumberland, Maryland. 

 Cotypes.C&t. No. 53287, U.S.N.M. 



PORAMBONITES OBSCURUS Hall and Whitfield. See Parastrophia(?) obscura. 

 PORAMBONITES? OTTAWAENSis Billings. See Rhynchotrema ottawaense. 

 PORCELLIA (part) of authors. See Oxydiscus Koken. 

 PORCELLIA ORNATA Sharpe. See Cyrtolites ornatus. 

 PORCELLIA SENEX Winchell and Marcy. See Platyceras senex. 

 PORITES? ASTRAFORMIS Owen. See Plasmopora follis. 

 PORITES INORDINATA Lonsdale. See Heliolites inordinata. 

 PORITES MEGASTOMA McCoy. See Heliolites megastoma. 

 PORITES PETALLIFORMIS Lonsdale. See Plasmopora petaliformis. 

 PORITES? VETUSTA Hall. See Protarsea vetusta. 



POROCRINUS Billings. Genotype: P. conicus Billings. 



Porocrinus Billings, Geol. Surv. Canada, Rep. Progr. for 1853-56, 1857, p. 279; 

 Geol. Surv. Canada, dec. 4, 1859, p. 33, fig. 13. Meek and Worthen, Proc. 

 Acad. Nat. Sci. Philadelphia, 1865, p. 145; Geol. Surv. Illinois, 3, 1868, 

 p. 329. Zittel, Handb. Pal., 1, Munich, 1879, p. 420. Grant, Trans. Ottawa 

 Field Nat. Club, 1, 1881, p. 42. Miller, N. A. Geol. Pal., 1889, p. 273; Zittel- 



