168 
NATJTILOIDEA. 
OHDOYICIAN SPECIES. 
Actinoceras Bigsbyi, Bronn\ 
1824. Ortliocerce . . . Bigsby, Trans. Geol. Soc. ser. 2, vol. i. p. 198, 
pi. XXV. fF. 1, 2 (excl. f. 3). 
1837. Actinoceras Bigshyi^'S>YQ\m^ Lethsea Geogu. Bandi. p. 98, Taf. i. 
f. 8 (after Bigsby). 
1840. Actinoceras Bigshii, Stokes, Trans. Geol. Soc. ser. 2, vol. v. 
pt. 3, p. 707 (with reference to Trans. Geol. Soc. 1824, loc. cit.). 
1840. Actinoceras Lgonii'^, Stokes, Trans. Geol. Soc. ser. 2, vol. v. 
pt. 3, p. 707, pi. lix. f. 1. ^ 
1843. Actinoceras Lyonii, Castelnau, Syst. Sil. de I’Amerique Septen- 
trionale, p. 32, pi. ix. f. 4. 
1847. Ormoceras tenuijilum^ Hall, Pal. of New A"ork, vol. i. p. 5o, 
pi. XV., pi. xvi., pi. xvii. f. 1, a, h. 
1853. Actinoceras Bigshyi, Saemann, Ueber die Nautiliden, in Palaeon- 
tograpbica. Band iii. p. 150, pi. xviii. 
1860. Actinoceras Bigshyi, Eicbwald, Lethsea Kossica, vol. ii. Seconde 
Sect, del’ancienne Periode, p. 1253. 
1861. Ormoceras Lyotiii, Hector, Quart. Joiim. Geol. Soc. vol. xvii. 
p. 439 (Salter’s determination). 
1863. Orthoceras Bigshyi, Billings, Geol. of Canada, p. 149, ff. 107, a, b, 
and Appendix, p. 949. 
1866. Orthoceras {Ormoceras') temiijilum, Barrande, Syst. Sil. de la 
Bobeme, vol. ii. Texte iii. 1874, p. 7554, pi. ccxxxvii. fP. 6-7. 
1869. Orthoceras Bigshyi, Salford, Geol. of Tennessee (Trenton and 
Nashville Series), p. 289. 
1874. Orthoceras {Actinoceras) Bigshyi, Barrande, Syst. Sil. de la 
Bobeme, vol. ii. Texte iii. p. 734, pi. ccxxxi. ff. 4, 5 (after Bigsby, 
loc. cit.), pi. ccccxxxvii. ff. 10-16. 
1876. Orthoceras Bigshyi, Chapman, Outlines of the Geol. of Canada, 
Introduction, p. xxiv. 
1880. Actinoceras Lyoni, Wbiteaves, Geol. Surv. of Canada, Beport for 
1878-79, pp. 46c, 48c, Appendix i. 
1883. Ormoceras tenuijilum (?), Whitfield, Geol. of Wisconsin, vol. iv. 
pt. ii. p. 372. 
other words that the same relative succession of events prevailed in the two 
areas, though not at the same time. Whichever view is adopted, I think there 
can be little doubt that some old shore-line or shallow sea must have stretched 
across the North Atlantic or Arctic Oceans, along which the forms migrated 
from one province to the other, and that some barrier must have cut off this 
area from Wales and Central Europe.” 
^ Barrande {infra) makes Stokes the author of this species ; but that is not 
correct, because Stokes did not describe it until 1840, that is three years after 
the publication of Bronn’s name — A. Bigshyi — which Stokes himself adopted. 
^ Named after Captain Lyon, who collected specimens at Igloolik, in Ai’ctic 
America, where Sir Edward Parry’s Expedition wintered in 1822-23. 
