BIBLIOGRAPHIC LIST OF GENERA AND SPECIES, 431 



DiDTMOGRAPTUS DivARiCATUS Nicholson. See Dicellograptus divaricatiis. 



DiDTMOGRAPTUS? ELEGANs Ruedemann. See Monograptus elegans. 



Didymograptus ellesee Ruedemann. 



Didymograptus (Leptograptus) (part.) Ruedemann, New York State Pal. Ann. 



Rep., 1902, p. 589. 

 Didymograptus ellesi Ruedemann, Mem. New York State Mas., 7, 1904, pt. 1, 



pp. 682, 683, pi. 14, figs. 22-24, text figs. 75, 76. (Con-ected to elles* in 1908, 



Mem. 11, pt. 2, p. 134.) 

 Canadian (Deepkill, Didj'mograptus bifidus zone): Deepkill, Rensselaer County, 



New York. 



Didymograptus euodus Lapworth. 



Didymograptus euodus Lapworth, Quart. Jour. Geol. Soc. London, 31, 1875, p. 



645, pi. 35, fig. la-c— Elles and Wood, Mon. British Grapt., pt. 1, Pal. Soc, 



p. 21, pi. 1, figs. 10a, b. 

 Ordovician (Lower Llandeilo): Abereiddy Bay, St. David's District, Wales. 

 Canadian (Upper Tetragraptus zone): Twelve miles west of Little Rock, Arkansas. 



Didymograptus extensus (Hall). 



Graptolithus extensus Hall, Geol. Surv. Can. Rep., 1858, p. 132; Canadian Nat. 

 Geol., 3, 1858, p. 166; Geol. Surv. Canada, dec. 2, p. 80, pi. 2, figs. 11-16. 



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

 Hist., 1868, p. 195, pi. 3, fig. 12; rev. ed., 1870, p. 225, pi. 3, fig. 12, p. 228. 



Didymograptus extensus Nicholson, Ann. Mag. Nat. Hist., 4th ser., v. 1870, 5, 341, 

 pi. 7, figs. 2, 2a.— Hopkinson, Quart. Jour. Geol. Soc, 31, 1875, p. 642, pi. 33, 

 figs. la-Id. — Brogger, Die Sil. Etagen 2, 3, 1882, p. 40, Kristiania. — Herrmann, 

 Geol. Mag., dec. 3, 3, 1886, p. 14.— Lapworth, Proc and Trans. Roy. Soc Can., 

 4, 1887, pp. 168, 184.— Ami, Geol. Sur. Can. Rep., 2d ser., 3, pt. 2, 1889, p. 

 116k.— Roemer and Freeh, Leth. Pal., 1, 1897, p. 591.— Elles, Quart. Jour. 

 Geol. Soc, London, 54, 1898, p. 504. — Tornquist, Lunds Univ. Arsskrift, 37, 

 Af. 2, Nr. 5, 1901, p. 14, pi. 1, figs. 25-30.— Elles and Wood, Mon. British 

 Grapt., pt. 1, Pal. Soc, 1901, p. 8, pi. 1, figs, la, b., text figs. 4a-d. — Ruede- 

 mann, New York State Pal., Ann. Rep., 1902, p. 556; Mem. New York State 

 MuB., 7, pt. 1, 1904, pp. 668-671, pi. 13, figs. 17, 18; pi. 14, figs. 1-4; text 

 figs. 62-65. 



Didymograpsus extensus Gurley, Jour. Geol., 4, 1896, p. 96 (gen. ref.). 



Graptolites (Didymograptus) extensus McCoy, Geol. Surv. Victoria, Prodr. Pal., 

 dec. 2, 1875, p. 29, pi. 20, figs. 1, la. 



Graptolithus constrictus Hall (part), Geol. Surv. Canada, Can. Org. Rem., dec 2, 

 1865, p. 76, pi. 1, figs. 23-27. 



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

 laer County, New York (Deepkill, Tetragraptus zone); Arkansas; South 

 Scotland; Wales (Arenig); Wales (Skiddaw); Christiania; Scania; Australia. 

 Didymograptus extenuatus (Hall). 



Graptolithus extenuatus Hall, Geol. Surv. Canada, dec 2, 1865, p. 75, pi. 1, 

 figs. 21, 22. 



GraptoUthus (Monoprion) extenuatus Hall, 20th Rep. New York State Cab. Hist., 

 1868, p. 226; rev. ed., 1870, p. 241. 



Didymograpsus extenuatus Gurley, Jour. Geol., 4, 1896, p. 96 (gen. ref.). 



Didymograptus extenuatus Elles and Wood, Mon. British Grapt., Pal. Soc, 1903, 

 p. li (gen. ref.). 



Canadian (Levis, Diplograptus dentatus zone): Point Levis, Quebec. 



