Echinoderma. 453 



Perischodomns, M'Coy Aunals N. H. III. 8. 244. 1849. 



PERISCHOECHINIDA. Foss. 

 Petraster, Billings Fig. etc Canad. Org. Remaius Dec. III. 79. 4858. 



ASTERIDA. Foss. 



Petricia, Gray AnnalsN. H. XX. 193. 1847 ASTERIDA. 



Phanogenia, Loyeu Consp. Soc. R. Suec Sc Act. XXIII. 9. 1866. 



CRINOIDEA. 

 Phialocrinus, Eichwald Moscou Soc Imp. des Nat. XXIX. 114. 1856. 



CRINOIDEA. Foss. 

 Philocrinus, De Koninck Quart. Journ. Londou Geol. Soc. XIX. 4. 1863. 



CRINOIDEA. Foss. 



Phymechinus, DesorSynops. Echin. foss. 1858 ECHINID A. i^oss. 



Pileus, Desor Syuops. Echin. foss. 1858 ECHINIDA. Jbss. 



Pilidium, J.MiiUer Arch. 159. 1847 



Pisocrinus, De Koninck Bull. Acad. Belge 55. 1858. . CRINOIDEA. Foss. 

 Platybryssus, Grube Jahrsber. d. ."schles. Ges. XLIII. 61. 1866. ECHINIDA. 

 Pleurocystites, Billings Canada Geol. Survey Dec. IV. 50. 1854. 



CYSTIDEA. Foss. 



Pluteus, J. Muller Arch. 101. 1846. = Larra Ophiitrae,s,^. I. c. 160. 1847. 



= Larva Kchinidae cnjusdam secundum J. Miiller Wiegmann Arch. 



1848, 1850 et 1851 etKrohuibidem 1851 ASTERIDA. 



Porocidaris, Desor Syuops. Echiu. foss. 1858 ECHINIDA. Jbss. 



Porocrinus, Billiugs Cauada Geol. Survey Dec. 17. 33. 1859. 



CRINOIDEA. Foss. 

 Porosoma, Cotteau Bull. Soc. Geol. de France XIII. 646. 1856. 



ECHINIDA. Foss. 

 Pradocrinus, De Verneuil Bull. Soc geol. de France VII. 184. 1850. 



CRINOIDEA. Foss. 



Prenaster, Desor Synops. Echin. foss. 1 858 ECHINIDA. lbs«. 



Pseudodiadema, Desor Synops. I^hiu. foss. 1858. . . . ECHINIDA. Foss. 



Psilechinus, Liitkeu Misc H. N. Hafn. 25. 1 864 ECHINIDA. 



Ptilonaster, J. Hall XX. Report State Cab. N. H. 1866. . ASTERIDA. Foss. 



I^andasia, GrayAunalsN. H. XX. 193. 1847 ASTERIDA. 



Ravenellia, LiitkeuMiscH.N.Hafu. 104. 1864 ECHINIDA. 



Reteocrinus, Billings Canada Geol. Survey Dec. IV. 63. 1859. 



CRINOIDEA. Foss. 

 Rhabdocidaris, Desor Synops. Echin. foss. 1858. . . . ECHINIDA. Foss. 

 RhabdomolgUS, Kefersteiu Zeitschr. f. wiss. Zool. XII. 34. 1861. 



HOLOTHURIDA. 

 Rhizocrinus, Sars Forh. Christiana Ved. Selsk. 127. 1865. . CRINOIDEA. 

 Rhopalocoma, J. W. Salter Ann. N. H. XX. 321. 1857. . ASTERIDA. Foss. 



Rhopalodina, Gray 1848. . . . HOLOTHURIDA. 



Rumpfia, Desor Synops. Echin. foss. 1858 ECHINIDA. Foss. 



Saccocrinus, J. Hall Geol. of New-York IL 205.1853. CRINOIDEA. Foss. 



Savignyia, Desor Syuops. Echin. foss. 1858 ECHINIDA. JPoss. 



Scaphiocrinus, Hall et Whitney Geol. Surv. of Jowa I. 549. 1858. = Gra- 



pAiocrintfs,Le E.oi\eiT>eKon.? CRINOIDEA. Foss. 



Sclerodactyla, Stimpsou Proc Bostou Soc IV. 6. 1848. . HOLOTHURIDA. 



Sismondia, Desor Syiiops. Echiu. foss. 1858 ECHINIDA. Fo.<(s. 



Sphaerechinus, Desor Synops. Echin. foss. 1858. . . . ECHINIDA. Foas. 

 Sphaerocrinus, F. Roemer fiheinl. Westph. Naturh. Ver. VIII. 369. 1851. 



CRINOIDEA. Foss. 



