202 



CCELENTERATA. 



[PVC. RHI. 



fulcratum, Hall, 1882, Foss. Corals Niagara 

 and Up. Held. Grs., p. 6, and 35th Rep. 

 N. Y. St. Mus. Nat. Hist., p. 410, Ni- 

 agara Gr. 



infundibilum, Meek, 1877, U. S. Geo. Sur. 

 40th Parallel, vol. 4, p. 28, Devonian. 



FIG. 211. Ptychophyllum knappi. 



knappi, Hall, 1883, 12th Rep. Geo. Ind., 



p. 278, Up. Held. Gr. 

 stokesi, Edwards & Haime, 1851, Brit. 



Foss. Corals, p. Ixix, Niagara Gr. 

 striatuni, Hall, 1882, Foss. Corals Niagara 

 and Up. Held. Grs., p. 22, and 35th 

 Rep. N. Y. St. Mus. Nat. Hist., p. 426, 

 Up. Held. Gr. 



versiforme, Hall, 1882, Foss. Corals Ni- 

 agara and Up. Held. Grs., p. 22, and 

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

 426, Up. Held. Gr. 



PYCNOSTYLUS, Whiteaves, 1884, Pal. Foss., 

 vol. 3, p. 2. [Ety. puknos, dense ; 

 stylos, column.] Corallum aggregate ; 

 corallites slender, divided by calicular 

 gemmation, at distant intervals, into 

 sets of three or more ascending 

 flexuous branches ; structure similar to 

 Amplexus, but tabulae horizontal and 

 uot embracing. Type P. guelphensis. 

 elegans, Whiteaves, 1884, Pal. Foss., 

 vol. 3, p. 4, 

 Guelph Gr. 

 g u e 1 p h e nsis, 

 Whiteaves, 

 1884, Pal. 

 Foss., vol. 3, 

 p. 3, Guelph 

 Gr. 



Quenstedlia, Ro- 

 minger, 1876, 

 Foss. Corals, 

 p. 71. Being 

 preoccupied , 

 Nicholson 



KIQ. 212. Pycnostylus 

 guelpheusis ; two brunches 

 are brokeu off at C, C. 



proposed Romingeria. 

 niagarensis, see Romingeria niagarensis. 



RASTRITES, Barrande, 1850, Graptolites de 

 Boheme, p. 64. [Sig. a rake.] Small, 

 almost linear, 

 very long, 

 stipe slightly 

 curved ; in- 

 terior canal 

 connecting 

 the cellules, 

 which are on 

 the convex 



each other. 



Type R. peregrinus. 

 barrandi, Hall, 1859, Pal. N. Y., vol.. 3, p 



521, Hud. Riv. Gr. 

 RETIOGRAPTUS, Hall, 1865, Dec. 2, Org. Rem., 



p. 115. [Ety. rete, net ; grapho, I write.] 



Frond simple or compound ; stipes 



numerous arranged bilaterally on an 



axis, elongate, oval or lanceolate with 



longitudinal axis and reticulate struc- 



ture ; margins with mucronate points. 



.Type R. tentaculatus. 

 barrandi, Hall, 1860, 13th Rep. N. Y. St. 



Mus. Nat. Hist., p. 61, Hud. Riv. Gr. 

 eucharis, Hall, 1865, Can. Org. Rem., Dec- 



ade 2, p. 146, Utica Slate. 

 geinitzanus, Hall, 1859, Pal. N. Y., vol. 3, 



p. 518, Hud. Riv. Gr. 

 tentaculatus, Hall, 1858, (Graptolithus 



tentaculatus,) Rep. of Prog. Can. Geo. 



Sur., p. 134, and Dec. 2, Org. Rem., p. 



116, Quebec Gr. 



RETIOLITES, Barrande, 1850, Graptolites de 

 Boheme, p. 68. [Ety. rete, 

 net; lithos, stone.] Stipes 

 thin, flat, elongate, triangu- 

 lar, composed of two series 

 of cellules symmetrically 

 arranged, in regard to the 

 axis; orifices on the sides of 

 the triangle. Type R. gei- 

 nitzanus. 



ensifprmis, Hall, 1858, (Grap- 

 tolithus ensiformis,) Rep. of 

 Prog. Can. Geo. Sur., p. 133, 

 and Decade 2, Org. Rem., p. 

 114, Quebec Gr. 

 venosus, Hall, 1852, (Graptolithns veno- 



sus.) Pal. N. Y., vol. 2, p. 40, Clinton Gr. 

 RHIZOGR APTUS, 



Spencer, 1878, 



Can. Nat., 



vol. 8, p. 460. 



[Ety. rhiza, 



root ; grapho, 



I write.] Cy- 



athiform, bi- 



fu rcating 



branches 



with dichoto- 



mous termi- 



nations and 



more or less FlG 215. Rhizograptus bul- 



reticulate; 



stem terminating in a bulb. Type R. 



bulbosus. 



FIG. 2H.-Re 

 tlolltes ve- 

 nosus. 



