POTEKIOCEKATID^. 
259 
Horizon. Trenton and Hudson Eiver ( = Bala Limestone?). 
Localities. Hontmorenci, near Quebec; Middleville, Hew York 
State (Trenton) ; Hottawasaga, Simcoe Co., Canada West (Hudson 
River). 
A\ eR represented in the Collection, most of the specimens having 
been presented by Dr. ,T. J. Rigsby, F.E.S. 
CAEBOHTFEEOUS SPECIES. 
Poterioceras fusiforme, J. de C. Sowerby, sp. 
1829. Orthocera fusiformis, J, de C. Sowerby, Min. Conch, vol. vi. 
p. 167, tab. dhvxxviii. f. 1. (excl. f. 2). 
183G. Orthoceras fusiforme, Phillips, Geol. of Yorkshire, pt. ii. p. 238, 
pi. xxi. ff. 14, 15. 
1844. Poterioceras fusiforme, M^Cov, Synop. Carb. Foss, of Ireland, 
p. 10. 
1844. Apioceras fusiforme, Fahrenkohl, BuU. de la Soc. Imp. des 
Natur. de Moscou, vol. xvii. p. 781. 
1848. Orthoceras fusiforme, Bronn, Nomencl. Palfeont. p. 864. 
1849. Gomplioceras fusiforme, d’Orbigny, Prodi’. de Paleont. Stratigr. 
vol. i. p. 112. 
1852. Gomphoceras fusiforme, Giebel, Fauna der Vorwelt, Band hi. 
Abth. i. p. 216. 
1854. Poterioceras fusiforme, Morris, Cat. of British Foss. 2nd ed. p. 312. 
1855. Orthoceras {Poterioceras) fusiforme, MHoy, British Pal. Foss, 
fasc. hi. p. 569. 
? 1850. Gomphoceras laejena, Eichwald, Bull, de la Soc. Imp. des Natur. 
de Moscou, p. 183. 
? I860. Gomphoceras laejena, Eichwald, Lethsea Eossica, vol. i. Seconde 
Sect, de I’ancienne P^riode, p. 1269, pi. xlviii. f. 16. 
1862. Poterioceras fusiforme, Griffith, Journ. Geol. Soc. of Dublin, 
vol. ix. p. 55. 
1876. Poterioceras fusiforme, Armstrong, Young, and Robertson, Cat. 
of the Western Scottish Fossils, p. 59. 
1880. Gomphoceras fusiforme, de Koninck, Faune du Calc. Carb. de la 
Belgique, pt. ii. p. 42, pi. xxxvii. ff. 4, a-c. 
Sp. Char. Shell slender, very slightly curved, gradually expanding 
from the very slender (imperfect) apical extremity to within a short 
distance of the aperture ; but before the latter is reached there is a 
weU-marked constriction. The complete margin of the aperture has 
not been seen. The section of the shell is elliptical, making due 
allowance for the compression which many specimens have evidently 
undergone. The length of the body-chamber appears to be at least 
5 that of the entire shell, but this measurement is only approximate, 
s 2 
