300 



MOLLVSCOIDA. 



[cva kna. 



Cystopora, Hall, 1881, Bryozoans of Up. 

 Held. Gr., p. 19. [Ety. kustis, bladder ; 

 poros, pore.] Simple or branching sub- 

 cylindrical stipes ; cells arising from the 

 axis ; circular and snbcylindrical below, 

 enlarged above the middle and becom- 

 ing ampullate, turning abruptly out- 

 ward below the apertures, which are 

 extremely contracted; cell-tubes ex- 

 posed more than half their length. 

 Type C. geniculata. 



geniculata. Hall, 1881, Bryozoans of the 

 Up. Held. Gr., p. 20, and Pal. N. Y., vol. 

 6, p. 103, Up. Held. Gr. 

 Diamksopora, Hall, 1852, Pal. N. Y., vol. 2, 

 p. 158, and vol. 6, p. 19. [Ety. diame- 

 sos, the part between ; poros, opening.] 

 Ramose, hollow, epitheca on inner sur- 

 face ; intercellular space solid ; surface 

 like Trematopora. Type D. dichotoma. 



camerata, Hall. 18813, (Trematopora came- 

 rata,) Rep. St. Geol. and Pal. N. Y., 

 vol. 6, p. 72, Up. Held. Gr. 



communis, Ulrich, (in press,) Geo. Sur. 

 111., vol. 8, pi. 39 and 41, Utica Slate. 



constricta, Hall, 1874, (Trematopora con- 

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

 Hist., p. 104, Low. Held. Gr. 



dichotoma, Hall, 1853. I'al. N. V., vol.2, 

 p. 158, Low. Held. Gr. 



dispersa, Hall, 1879, (Trematopora dis- 

 perse ) 32d Rep. N. Y. St. Mus. Nat. 

 Hist., p. 150, Low. Held. (ir. 



vaupeli, Ulrich, (in prees,) Geo. Sur. 111., 

 vol. 8, pi. 39 and 41, Utica Slate. 

 Dichotrypa, Ulrich, (in press,) Geo. Sur. 

 111., vol. 8, p. 386. [Ety. dicha, double; 

 trupa, opening.] Consisting of large 

 bifoliate expansions; the surface with 

 solid maculae ; zouicial and minute struc- 

 ture as in Cystodictya. Type D. foliata. 



elegans, Ulrich, (in press,) Geo. Sur. 111., 

 vol. 8, pi. 76, St. Louis < i i . 



expatiata, Ulrich, (in press,) Geo. Sur. 

 111., vol. 8, St. Louis Qr. 



flabellum, Rominger, 1866, (Fistulipora 

 flabellum,) Proc. Acad. Nat. Sci., Phil., 

 p. 9, St. Louis Gr. 



foliata, Ulrich, (in press,) Geo. Sur. 111., 

 vol. 8, pi. 42, Ham. Gr. 



grandis, Ulrich, (in press,) Geo. Sur. 111., 

 vol. 8, pi. 42, Niagara Gr. 



intermedia, Ulrich, (in press,) Geo. Sur. 

 111., vol. 8, pi. 76, St. Louis (Jr. 



lyroides, Ulrich, (in press,) Geo. Sur. 111., 

 vol. 8, pi. 77, St. Louis Gr. 

 Dicranopora, Ulrich, 1882, Jour. Cin. Soc. 

 Nat. Hist., vol. 5, p. 166. [Ety, di- 

 kranos, two-pointed ; poros, pore.] Zo- 

 arium like Stictopora, but distinguished 

 by being composed of ligulate joints, 

 the edges being subparallel to near the 

 upper end, when they diverge and bear 

 two segments; cell-mouths between 

 raised longitudinal lines ; no interstitial 

 cells. Type D. internodia. 



emacerata, Nicholson, 1875, (Ptilodictya 

 emacerata,) Pal. Ohio, vol. 2, p. 261, 

 Hud. Riv. Gr. 



fragilis, Billings, 1866,(Ptilodictyafragilis,) 

 Catal. Sil. Foss. Antic, p. 9, Hud. 

 Riv. Gr. 



Fig. 471.— Dicrauopora internodia. Natural size 

 and magnitW'cl. 



internodia, Miller & Dyer, 1878, \ Ptilo- 

 dictya internodia,) Cont. to Pal., No. 2, 

 p. 7, Hud. Riv. Gr. 



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

 Hist., vol. 5, p. 166, Hud. Riv. (ir. 



nitidula, Billings, 1866, I Ptilodictya niti- 

 dula,) Catal. Sil. Foss. Antic, p. !), 

 Hud. Riv. Gr. 



trentonensis, Ulrich, 1882, Jour. Cin. Soc. 

 Nat. Hist., vol. 5, p. 167, Trenton (Jr. 

 Dipi.oclema, Ulrich, (in press,) Geo. Sur. 

 III., vol. 8, p. 3<>s. [Ety. diploos, double ; 

 klerna, twig.] Ramose, ovate in cross 

 section ; zooecia tubular, long, appar- 

 ently moniliform proximally; separated 

 internally by an axial lamina, from 

 which they gradually diverge to open 

 on the two sides of the compressed 

 branches; apertures prominent, isolated, 

 somewhat const riitcd and circular ; ex- 

 ternal wall thin. Type l>. trentonente. 



trentonense, Ulrich, (in press,) Geo. Sur. 

 111., vol. 8, pi. 53, Trenton Gr. 

 Diim.opoka, Young A Young, 187.">, Proc. 

 Nat. Hist. Soc. Glasgow. [Ety. diploot, 

 double; poros, pore.] Very slender 

 straight stems, throwing oil* a few lat- 

 eral branches of equal dimensions ; ob- 

 verse or poriferous side, with two 

 ranges of zotecia apertures, and moder- 

 ately developed medium keel ; reverse 

 striated. Type D. marginalis. 



bifurcata, Ulrich, (in press,) Geo. Sur. 

 111., vol. 8, pi. 62, Kaskaskia ( ir. 



biserialis, Ulrich, (in press,) Geo. Sur. 

 111., vol. 8, pi. 62, Low. Coal Meas. 

 Discotkypa, Ulrich, 1882, Jour. Cin. Soc. 

 Nat. Hist., vol. 5, p. 155. [Ety. diskos, 

 quoit; trupa, opening.] Free, thin, cir- 

 cular expansions; cells rhomboidal or 

 hexagonal; low monticules, with clus- 

 ters of large cells present ; no intersti- 

 tial cells or spiniform tubuli. Type D. 

 elegans. 



? devonica, Ulrich, 1886, Cont. to Am. Pal., 

 p. 25, Up. Held. Gr. 



elegans, Ulrich, 1879, (Chetetes elegans,) 

 Jour. Cin. Soc. Nat. Hist., vol. 2, p. 130, 

 Hud. Riv. Gr. 

 Enallopora, D'Orbigny, 1850, Prodr. d. Pa- 

 lfeont., t. 1, p. 22. [Ety. enallos, changed ; 

 poros, pore.] Small bifurcating branches, 

 without connecting bars; cell-mouths 



