BIBLIOGRAPHIC LIST OF (lENEEA AND SPECIES. 435 



Didymogriiptus sagitticaulis — Conthmed. 



Didyinograpsus convexus Giirley, Jour, (leol., 4, 1896, p. 67, pi. 5, fig. 8. 

 Didymogiaptus sagitticaulis Ruedemann, Mem. New York State Mua., 11, pt. 2- 



1908, pp. 248-251, pi. 14, fig. 3, text figs. 151-155. 

 Chazyan (Normauskill): Kenwood, Stockport, and near Poughkeepsie, New York; 



Canada; Arkansas (Striugtown); Tennessee (Athens). 

 I'lcsiotijpes.— Cat. No. 54255, U.S.N.M. (Gurley types of D. convexus.) 



Didymograptus serratulus (Hall). 



Graptolithus serratulus Hall, Pal. New York, 1, 1847, p. 274, pi. 74, fig. 5a, b.— 

 Chapman, Canadian Jour., n. e., 1, 1856, p. 390, text fig. 8— Hall, New York 

 State Cab. Nat. Plist., 20th Rep., 1867, p. 223f.— Walcott, Trans. Albany 

 Inst., 10, 1883, p. 35 (adv. sheets, 1879). 



VGraptolithus (Monograptus) serratulus Whitfield, U. S. Geog. Surv., 100th Mer.* 

 Lieut. A^Tieeler's Rep., 4, 1877, p. 19. 



Graptolithus (Monoprion) serratulus Hall, 20th Rep. New York State Cab. Nat. 

 Hist., 1868, p. 226; rev. ed., 1870, p. 260. 



Didymograptus serratulus Walcott, Geol. Soc. Amer.,Bull. 1 , 1890, p. 338. — Gurley 

 Geol. Surv. Arkansas, Ann. Rep., 3, 1892, p. 411. — Roemer and Freeh, Leth 

 Pal., 1, 1897, p. 589.~Ruedemann, Bull. New York State Mus., 42, 1901, pp 

 497, 541.— Elles and Wood, Mon. British Grapt., pt. 1, 1901, p. 29, pi. 2, figs 

 7a, b, text fig. 18a-b. — Ruedemann, Mem. New York State Mus., 11, pt. 2 

 1908, pp. 251-253, pi. 14, fig. 4, text figs. 156-159. 



Didymogi-apsus serratulus Pictet, Traite de Pal., 2d ed., 4, 1857, p. 474, pi. 108, 

 fig. 23. 



Middle Ordovician: Kenwood, Stockport, etc.. New York; Arkansas (Normans- 

 kill); Great Britain (Glenkiln). 



Didymograptus serratulus juvenalis Ruedemann. 



Didymograptus serratulus juvenalis Ruedemann, Mem. New York State Mus., 11, 



pt. 2, 1908, p. 252, fig. 156. 

 Chazyan (Normauskill): Kenwood, New York. 



DiDYJioGRAPTus SEXTANS Nicholsou. See Dicellograptus sextans. 



Didymograptus similis (Hall). 



Graptolithus similis Hall, Geol. Surv. Canada, dec. 2, 1865, p. 78, pi. 2, figs. 1-5. 



Didymograpsus similis Gurley, Jour. Geol., 4, 1896, p. 295 (gen. ref.). 



Didymograptus similis Ruedemann, New York State Pal., Ann. Rep., 1902, pp. 

 566, 567; Mem. New York State Mus., 7, pt. 1, 1904, pp. 677-679, pi. 14, 

 figs. 25-29, text figs. 73, 74 (73 on p. 678). 



Canadian: Point Levis, Quebec (Levis, Didymograptus zone); Deepkill, Rens- 

 selaer County, New York (Deepkill, Didymograptus and Diplograptus zones); 

 Wales (Arenig); Norway; Sweden. 



Didymograptus spinosus Ruedemann. 



Didymograptus spinosus Ruedemann, Mem. New York State Mus., 7, pt. 1, 1904, 



pp. 688, 689, pi. 14, figs. 30-32, text figs. 84, 85. 

 Canadian (Deepkill, Diplograptus dentatus zone): Mount Moreno, Columbia 



County, New York. 



Didymograptus subtenuis (Hall). 



Graptolithus tenuis (Portlock?) Hall, Pal. New York, 1, 1847, p. 272, pi. 74, figs. 



2a-d. 

 Graptolithus subtenuis Hall, in ililler's Amer. Pal. Foss., Isted., 1877, p. 244.— 



Walcott, Trans. Albany Inst., 1883, 10 (adv. sheets, p. 35). — Gurley, Jour. 



Cincinnati Soc. Nat. Hist., 16, 1892, p. 156. 



