PRA. — PTY.J 



CCELENTERATA. 



201 



astrsei/ormis, Owen, 1840, Rep. on Min- 

 eral lands, Devonian. This may be the 

 same species subsequently described as 

 Pachyphyllum woodmani. 



pyriformis, as identified by d'Archiac & 

 Verneuil, not American. 



vetustus, see Protarea vetusta. 

 Prasopora, Nicholson & Etheridge, 1877, 

 Ann. and Mag. Nat. Hist., 4th ser., vol. 

 20, p. 38. [Ety. prason, sea-plant ; poros, 

 pore.] Corallum compound, concavo- 

 convex or hemispheric ; corallites radi- 

 ating from a wrinkled basal epitheca ; 

 larger and smaller corallites intermin- 

 gled throughout the colony ; no monti- 

 cules ; corallites thin- walled, prismatic; 

 large ones with an exterior zone of 

 vesicular tabula; surrounding a vacant 

 central tube, which may be crossed by 

 an occasional tabula ; smaller ones ar- 

 ranged in a zone around the larger ones, 

 and crossed by numerous, close-set, com- 

 plete, horizontal tabula?. Type P. grava?. 



affinis, Foord, 1883, Cont. to Micropaheon- 

 tology, p. 12, Trenton Gr. 



conoidea, Ulrich, 1886, 14th Rep. Geo. 

 Sur. Minn., p. 87, Trenton Gr. 



contigua, Ulrich, 1886 , 14th Rep. Geo. 

 Sur. Minn., p. 87, Trenton Gr. 



newberryi, Nicholson, 1875, (Chetetes 

 newberryi,) Ohio Pal., vol. 2, p. 212, 

 Hud. Riv. Gr. 



nodosa, Ulrich, 1882, Jour. Cin. Soc. Nat. 

 Hist., vol. 5, p. 245, Hud. Riv. Gr, 



oculata, Foord, 1883, Cont. to Micro- 

 pala>ontology, p. 11, Trenton Gr. 



selwyni, Nicholson, 1881, (Monticulipora 

 selwvni,) Struct, and Affin. of Montic, 

 p. 206, Trenton Gr. 



selwyni var. hospitalis, Nicholson, 1881, 

 (Monticulipora selwyni var. hospitalis,) 

 Struct, and Affin. of Montic, p. 206, 

 Hud. Riv. Gr. 



simulatrix, Ulrich, 1886, 14th Rep. Geo. 

 Sur. Minn,, p. 85, Trenton Gr. 

 Prionotm, Nilsson, 1835, Leth. Suec. 



folium, see Diplograptus folium. 



pristis, see Diplograptus pristis. 

 Protarea, Edwards & Haime, 1851, Pol. 

 Foss. des Terr. Pal., p. 208. [Ety. 



Fig. 209.— Protarea vetusla, on Strophomena 

 alternata. 



protos, first; araios, porous.] Thin, in- 

 crusting ; calices equal, hexagonal, 



shallow ; septa 12, extending but slightly 

 into the visceral chamber ; walls thick. 

 Type P. vetusta. 



vetusta, Hall, 1847, (Porites vetustus,) 

 Pal. N. Y., vol. 1, p. 71, Trenton & Hud. 

 Riv. Grs. 



verneuili, Edwards & Haime, 1851, Pol. 

 Foss. des Terr. Pal., p. 209, Silu- 

 rian. (?) 

 Protograptus, Matthew, 1885, Trans. Roy. 

 Soc. Can., p. 31. [Ety. protos, first; 

 grapho, I write.] Stipes thin, flat, 

 elongate, dichotomously branched ; 

 having a central axis, and being alate 

 on each side ; pores arranged along the 

 axis of the stipe ; axis and margin of 

 the stipe connected by delicate nerv- 

 ules. Type P. alatus. 



alatus, Matthew, 1885, Trans. Roy. Soc. 

 Can., p. 32, St. John Gr. 

 Ptilograptus, Hall, 1865, Can. Org. Rem., 

 Decade 2, p. 139. (Ety. ptilon, feather ; 

 grapho, I write.] Plant-like, rooted, 

 simple or branching ; branches plumose, 

 pinnules alternate on opposite sides; 

 celluliferous on one face only ; branches 

 cylindrical or flattened. Type P. plu- 

 mosus. 



foliaceus, Spencer, 1878, 

 Can. Nat., vol. 8, and 

 Bull. No. 1, Mus. 

 Univ. St. Mo., p. 41, 

 Niagara Gr. 



geinitzanus, Hall, 1865, 

 Can. Org. Rem., De- FlG . 2 io.-Ptiiogia P - 

 cade 2, p. 140, Quebec tus foliaceus. 

 Gr. 



plumosus, Hall, 1865, Can. Org. Rem., De- 

 cade 2, p. 140, Quebec Gr. 

 Ptychonema, Hall, 1887, Pal. N. Y., vol. 6, 

 p. xiv. [Ety. jityche, wrinkle ; nema, 

 thread.] Massive or ramose, composed 

 of thin-walled, strongly corrugated cells, 

 which are apparently without dia- 

 phragms. Type P. tabulatum. 



helderbergias Hall, 1874, (Chetetes helder- 

 bergise,) 26th Rep. N. Y. St. Mus. Nat. 

 Hist., p. 110, Low. Held. Gr. 



t&bulatum, Hall, 1876, (Chetetes tabula- 

 turn,) Ulus. Dev. Foss., pi. 37, and figs. 

 16-19, and Pal. N. Y., vol. 6, p. 14, Up. 

 Held. Gr. 

 Ptychophyli.um, Lonsdale, 1839, Sil. Syst., 

 p. 691, and E. & H. Brit. Foss. Corals, 

 p. lxix. [Ety. ptyche, ridge , phyllon, 

 leaf.] Corallum simple, having infun- 

 dibuliform tabula- superposed and in- 

 vaginated ; septastrongly twisted toward 

 the center ,of the tabulae so as to con- 

 stitute a spurious columella. Type P. 

 stokesi. 



canadense, Billings, 1862, Pal. Foss., vol. 

 1, p. 107, Mid. Sil. Anticosti Gr., 

 Division 4. 



floriforme, Hall, 1882, Foss. Corals Ni- 

 agara and Up. Held. Grs., p. 5, and 

 35th Rep. N. Y. St. Mus. Nat. Hist., p. 

 409, Niagara Or. 



