860 BULLETIN 92, UNITED STATES NATIONAL MUSEUM. 



NUTTAINIA Eaton. See Cryptolithus Green. 



NUTTAINIA CONCENTRICA Eaton. See Cryptolithua tessellatus. 



NTCTOPORA Nicholson. Genotype: N. billingsi Nicholson. 



Nyctopora Nicholson, Tab. Corals Pal. Period, 1879, p. 182. Roemer, Leth. 

 geog., pt. 1, Leth. Pal., 1883, p. 423. Miller, N. A. Geol. Pal., 1889, p. 198. 

 Lambe, Cont. Can. Pal. Geol. Surv. Canada, 4, pt. 1, 1889, p. 48. 



Nyctopora billingsi Nicholson. 



Nyctopora Billingsii Nicholson, Tab. Corals Pal. Period, 1879, p. 184, pi. 9, figs. 

 3-3c. Lambe, Cont. Can. Pal. Geol. Surv. Canada, 4, pt. 1, 1889, p. 49, 

 pi. 2, figs. 1, la. Weller, Geol. Surv. New Jersey Pal., 3, 1903, p. 137, pi. 7, 

 figs. 1, 2. 



Columnaria Goldfussi Nicholson (not Billings, 1857), Pal. Ontario, 1875, p. 9. 



Trenton: Peterboro, Ontario; Jacksonburg, New Jersey. 



OBOLELLA Hall and Clarke (part). See Dicellomus Hall. 

 OBOLELLA? AMBIGUA Walcott. See Elkania ambigua. 

 OBOLELLA BELTI Davidson. See Acrotreta belti. 

 OBOLELLA DESIDERATA Billings. See Elkania desiderata. 

 OBOLELLA DISCOIDEA Hall and Whitfield. See Obolus discoidea. 

 OBOLELLA? GEMMULA Matthew. See Lingulella ferruginea. 

 OBOLELLA IDA Billings. See Elkania ida. 

 OBOLELLA? MINUTA Walcott. See Linnarssonella minuta. 

 OBOLELLA NANA Meek and Hayden. See Dicellomus nanus. 

 OBOLELLA PRETIOSA Billings. See Acrothele pretiosa. 

 OBOLELLA SALTERI Holl. See Obolus (Broggeria) salteri. 

 OBOLELLINA Billings. See Dinobolus Hall. 

 OBOLELLINA GALTENSIS Billings. See Rhinobolus galtensis. 



OBOLUS Eichwald. Genotype: O. apollinus Eichwald. 



Obolus Eichwald, Zoologia specialis, 1, 1829, p. 274. Davidson ibid, (part), 

 British Fossil Brach., 1, 1853, pp. 135-136; 3, pt. 7, 1866, p. 58. Hall and 

 Clarke, Pal. New York, 8, pt. 1, 1892, pp. 80, 81; ibid., pp. 337-339. 

 Walcott, Smiths. Misc. Coll., 53, 1908, pi. 11, pp. 142 and 144; Mon. U. S. Geol. 

 Surv., 51, pt. 1, 1912, p. 370. (See for complete bibliography.) Schu chert, 

 Zittel-Eastman Textb. Pal., 1, 1900, p. 306; ibid., 2d ed., 1913, p. 371. 



Lingulobolus Matthew, Trans. Roy. Soc. Canada, 2d ser., 1, 1895, pp. 260-261. 



Sphserobolus Matthew, Trans. Roy. Soc. Canada, 2d ser., 1, 1895, p. 263. 



Obolus (Lingulobolus) Walcott, Proc. U. S. Nat. Mus., 23, 1901, p. 683; Smiths. 

 Misc. Coll., 53, 1908, pi. 11, pp. 142, 144. 



Lingulobolus (subgenus of Obolus) Walcott, Mon. U. S. Geol. Surv., 51, pt. 1, 

 1912, p. 430. (Genotype: Lingulella? afnnis Billings.) 



Obolus (Broggeria) Walcott, Proc. U. S. Nat. Mus., 25, 1902, p. 605; Smiths. Misc. 

 Coll., 53, 1908, pi. 11, pp. 142, 144. 



Broggeria Walcott, Monog. U. S. Geol. Surv., 51, pt. 1, 1912, p. 424. (Genotype: 

 Qbolella salteri Hall.) 



