FOR. POT.] 



ECH1NODERMA TA. 



273 



squamosus, Billings, 1854, Can. Jour., 

 vol. 2, p. 251, and Can. Or<r. Rem., Dec- 

 ade 3, p. 49, Trenton Gr. 

 POKOCRINUS, Billings, 1857, Hep. of Progr. 

 . Geo. Sur. Can., p. 279. [Ely. from the 

 poriferous areas similar to pectinated 

 rhombs.] Calyx conical ; basals 5; sub- 

 radials 1x5; radios 1x5; azygous in- 

 terradials2; 

 pectinated 

 rhombs nu- 

 m e r o u s. 

 Type P. 

 conicus. 

 conicus, Bill- 

 ings, 1857, 

 Rep. of 

 Progr. Geo. 



Sur. Can., p. 279, and Can. Org. Rem., 

 Decade 4, p. 34, Trenton Gr. 



FIG. 400. Porocrinus conicus. 

 Diagram. 



FIG. 401. -Porocrinus crassus. Diagram. 



crassus, Meek & Worthen, 1865, Proc. 

 Acad. Nat. Sci. Phil., p. 115, and Geo. 

 Sur. 111., vol. 3, p. 330, Hud. Riv. Gr. 



pentaeonus, Meek 

 & Worthen , 

 1865, Proc. 

 Acad. Nat. Sci. 

 Phil., p. 146, 

 and Geo. Sur. 

 111., vol. 3, p. 

 332,TrentonGr. 



e m i t h i , Grant, 



1881, Trans. Ot- FIG. 402. Porocrinus cras- 

 tawa Field Nat- su s. One basal and two 

 uralists' Club, ^bradials enlarged. 

 No. 2, p. 42, Trenton Gr. 

 POTERIOCRINUS, Miller, 1821, Nat. Hist. Cri- 

 uoidea, p. 68. [Ety. poterion, goblet ; 

 krinon, lily.] Calyx obconical ; basals 5 ; 

 sub-radials 5 ; radials 1x5, with a varia- 

 ble number of smaller ones, the azygous 

 ray often having more than the others; 

 azygous plates 3 or 4, within the calyx, 

 succeeded by smaller ones that form 

 part of the ventral sac ; vault produced 

 in a long sac or proboscis , arms simple 

 or branching and bearing pinnules. 

 Type P. crassus. 



aaqualis, Hall, 1860, Supp. to Geo. Sur. 

 Iowa, p. 63, Burlington Gr. 



alternatus, see Dendrocrinus alternatus. 



anomalos, Wetherby, 1880, Jour. Gin. Soc. 



Nat. Hist., vol. 3, p. 158, Kaskas- 



kia Gr. 

 arachniformis, Worthen, 1882, Bull. No. 



1, 111. St. Mus. Nat. Hist., p. 13, and 



Geo. Sur. 111., vol. 7, p. 281, Keo- 



kuk Gr. 

 asper, Worthen, 1882, Bull. No. 1, 111. 



St. Mus. Nat. Hist., p. 11, and Geo. 



Sur. 111., vol. 7, p. 278, K^okuk Gr. 

 asperatus, Worthen, 1882, Bull. No. 1, 111. 



St. Mus. Nat. Hist., p. 12, and Geo. Sur. 



111., vol. 7, p. 280, Keokuk Gr. 

 barrisi, see Cyatbocrinus barrisi. 

 bayensis, see Scaphiocrinus bayensis. 

 bisselli, Worthen, 1873, Geo. Sur. 111., vol. 



5, p. 546, Kaskastda Gr. 

 briareus, see Scaphiocrinus briareus. 

 buffaloensis, Worthen, (in press,) Geo. 



Sur. 111., vol. 8, p. 89, Ham. Gr. 

 burketi, see Scaphiocrinus burketi. 

 bursiformis, White, 1862, Proc. Bost. Soc. 



Nat. Hist., vol. 9, p. 10, Burlington Gr. 

 caduceus, see Dt ndrocrinus caduceus. 

 calyculus, Hall, 1858, Geo. Sur. Iowa, p. 



553, Burlington Gr. 

 calyx, Hall, 1879, Desc. New Spec. Foss., 



p. 10, and llth Rep. Geo. Sur. Ind., p. 



266, Niagara Gr. 

 carbonarius, see Graph iocrinus carbo- 



FIG. 403. Poteriocrinos carinatus. Diagram. 



carinatus, Meek & Worthen, 1861, Proc. 



Acad. Nat. Sci. Phil., p. 139, and Geo. 



Sur. 111., vol. 3, p. 486, Burlington Gr. 

 clarkii, Williams, 1882, Proc. Acad. Nat. 



Sci. Phil., p. 21, Chemung Gr. 

 claytonensis, Worthen, 1882, Bull. No. 1, 



111. St. Mus. Nat. Hist., p. 18, and Geo. 



Sur. 111., vol. 7, p. 288, Warsaw Gr. 

 clytis, Worthen, 1882, Bull. No. 1, 111. St. 



Mus. Nat. Hist., p. 16, and Geo. Sur. 111., 



vol. 7, p. 294, St. Louis Gr. 

 columbiensis, Worthen, 1882, Bull. No. 1, 



111. St. Mua. Nat. Hist., p. 22, and 



Geo. Sur. 111., vol. 7, p. 293. Kaskas- 



kia Gr. 

 concinnus, Meek & Worthen, 1870, Proc. 



Acad. Nat. Sci. Phil., p. 26, and Geo. 



Sur. 111., vol. 5, p. 490, Keokuk Gr. 

 coreyi, Worthen, 1875, Geo. Sur. 111., vol. 



6, p. 516, Keokuk Gr. 

 cornellanus, Williams, 1882, Proc. Acad. 



Nat. Sci. Phil., p. 18, Chemung Gr. 



