DEN. DID.] 



CCELENTERATA. 



185 



prjegracilis, Spencer, 1884, Bull. No. 1, 



Mus. Univ. St. Mo., p. 19, Niagara Gr. 

 primordialis, Matthew, 1885, Trans. Roy. 



Soc. Can., p. 31, St. John Gr. 

 ramosus, Spencer, 1884, Bull. No. 1, Mus. 



Univ. St. Mo., p. 17, Niagara Gr. 

 simplex, Walcott, 1879, Utica Slate and 



related formations, p. 20, Utica Slate. 

 simplex, Spencer, 1S84, Bull. No. 1, Mus. 

 Univ. St. Mo., p. 17. The name was 

 preoccupied. See D. dubius. 

 spinosus, Spencer, 1884, Bull. No. l,Mus. 



Univ. St. Mo., p. 19, Niagara Gr. 

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

 cade 2, p. 129, Quebec Gr. 

 tenuiramosus, Walcott, 1879, Utica Slate 

 and related formations, p. 21, Utica 

 Slate. 



DENDROPORA, Michelin, 1846, Icon. Zooph., 

 p. 187. [Ety. dendron, tree; poros, 

 pore.] Corallum arborescent, with very 

 delicate, smooth branches; calices dis- 

 tant, and surrounded by a narrow, ob- 

 tuse margin ; septa small, but distinct. 

 Type D. explicita. 

 alternans, Roininger, 1876, Foss. Corals, 



p. 64, Ham. Gr. 

 neglecta, Rominger, 1876, Foss. Corals, p. 



63, Up. Held. Gr. 

 ornata, see Trachyppra ornata. 

 proboscidialis, Rominger, 1876, Foss. Cor- 

 als, p. 65, Ham. Gr. 

 reticulata, Rominger, 1876, Foss. Corals, 



p. 65, Ham. Gr. 



Dichograptus, syn. for Graptolithus. 

 DICRANOGRAPTUS, Hall, 1865, Can. Org. 

 Rem., Decade 2, p. 46. [Ety. dikranos, 

 two pointed ; grapho, I write.] The 

 lower part of the stipe has a row of 

 cells on each side, but above, the stipe 

 bifurcates, and has cells only on the 

 outer side of each bifurcation. Type D. 

 ramosus. 



divaricatus, Hall, 1859, (Graptolithus 

 divaricatus,) Pal. N. Y., vol. 3, p. 513, 

 Hud. Riv. Gr. 



furcatus, Hall, 1847, (Graptolithus fur- 

 catusj Pal. N. Y., vol. 1, p. 273, Utica 

 Slate. 



ramosus, Hall, 

 1847, (Grapto- 

 lithus ramo- 

 sus,) Pal.N.Y., 

 vol. 1, p. 270, 

 Utica Slate, 

 sextans, Hall, 

 1847, (Grapto- 

 lithus sextans,) 

 Pal. N. Y., vol. 

 1, p. 273, Utica 

 Slate. 



DlCTYONEMA, Hall, 



1852, Pal. N. Y., 

 FIG. 167. Dicranograptus vol. 2 p. 174. 

 ramosus. [Ety dictyon, 



net; nema, thread.] Fronds consisting 

 of flabelliform or funnel-shaped expan- 

 sions, composed of slender, radiating 

 branches, which frequently bifurcate 



as they recede from the base ; branches 

 united laterally by transverse dissepi- 

 ments; exterior striated; interior sur- 

 face celluliferous or serrate. Type D. 

 retiforme. 



expansum, Spencer, 1884, Bull. No. 1, 

 Mus. Univ. St. Mo., p. 25, Niagara Gr. 



fenestratum, Hall, 1851, in Foster and 

 Whitney's Rep. on Lake Superior Land 

 Dist., p. 223, Up. Held. Gr. 



gracile, Hall, 1852, Pal. N. Y., vol. 2, p. 

 175, Niagara Gr. 



grande, Nicholson, 1873, Ann. Mag. Nat. 

 Hist., 4th ser., vol. 12, Quebec Gr. 



irreguiare, Hall, 1865, Can. Org. Rem., 

 Decade 2, p. 136, Quebec Gr. 



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

 cade 2, p. 138, Quebec Gr. 



neenah, Hall, 1861, Geo. Rep. Wis., p. 17, 

 Trenton Gr. 



pergracile, Hall & Whitfield, 1872, 24th 

 Rep. N. Y. St. Mus. Nat. Hist, p. 181, 

 and Acad. Geo., p. 563, Niagara Gr. 



quadrangulare, Hall, 1865, Can. Org. Rem., 

 Decade 2, p. 138, Q.ipbec Gr. 



FIG. 168. Dictyonema retiforme. 



retiforme, Hall, 1843, (Gorgonia reti- 

 formis.) Geo. Rep. 4th Dist. N. Y., p. 

 115, and Pal. N. Y., vol. 2, p. 174, Ni- 

 agara Gr. 



robustum, Hall, 1865, Can. Org. Rem., 

 Decade 2, p. 137, Quebec Gr. 



splendens, Billings, 1874, Pal. Foss., vol. 

 2, p. 12, Gaspe limestone No. 1, Up. Sil. 



tenellum, Spencer, 1878, Can. Nat., vol. 

 8, and Bull. No. 1, Mus. Univ. St. Mo., 

 p. 26, Niagara Gr. 



websteri, Dawson, 1860, Can. Nat. and 

 Geo., vol. 5, and Acad. Geo., p. 563, 

 Niagara Gr. 



DIDYMOGRAPTUS, McCoy, 1851, Brit. Pal. 

 Foss., p. 3-9. [Ety. didymos, double; 

 grapho, I write.] Consisting of forked 

 stipes, straight or curved ; one cellu- 

 liferous side. Type D. murchisoni. 



