X 
INTRODFCTION. 
Kutoceratid^, Hyatt; 1883. 
Zittelloceras, Hyatt. Type, Cyrtoceras lamelhsum, Hall, Pal. New 
Yorii, vol. i. pi. xli. (1847). 
Halloceras, Hyatt. Type, Gyroceras undulatum, Hall, Pal. New 
York, vol. V. pt. ii. pis. liii., liv. (1879). 
Rutoceras, Hyatt. Type, Cyrtoceras Jason, Hall, Pal. New York, 
vol. V. pt. ii. pi. 1. (1879). 
Triplooceras, Hyatt. Type, Nautilus msperatus, Barr. Syst. Sil. Boh. 
vol. ii. pi. cccclxi. (1877). 
Adelphoceras, Barrande. Type, A. Bohemicum, Barr. Syst. Sil. Boh. 
vol. ii. pi. cccchx. (1870). 
Kophinoceras, Hyatt. Type, Cyrtoceras ornatum, d’Arch. and de 
Vern. Trans. Geol. Soc. vol. vi. pt. ii. pi. xxviii. (1841). 
Strophiceras, Hyatt. Type, Gyroceras binodosum, G. & F. Sandberger, 
Verstein. Nassau, pi. xii. (1850-56). 
Solenoceras, Hyatt. Type, Nautilus canaliculatus, Cox, in Owen, 
Geol. Kentucky, vol. hi. p. 575, pi. x. (1857). 
Phloioceras, Hyatt. Type, Nautilus gemmatus, Mojsisovics, Das 
Gehirge um Hallstatt, pi. hi. (1873). 
^Pleuronautilus, Mojsisovics. Type, P. trinodosus, Mojs. Mediterr. 
Triasprov. pi. Ixxxv. (1882). 
Eudoceratid.®, Hyatt, 1883. 
Eudoceras, Hyatt. Type, Trochoceras ? {Gonioceras ?) pandum, Hall, 
Pal. New York, vol. v. pt. ii. pi. cxi. (1879). 
Tripteroceras^ Hyatt. Tj^e, Orthoceras hastatum, Billings, Pep. 
Prog. Geol. Surv. Canada, 1853-1856, p. 333 (1857). 
Edaphoceras, Hyatt. Type, Nautilus ( Temnocheihis') Niotensis, Meek 
and Worthen, Geol. Surv. Illinois, vol. v. pi. xix. (1873). 
Endolohus, Meek and Worthen. T^’pe, Nautilus sjjectabilis. Meek 
and Worthen, Geol. Surv. Illinois, vol. ii. pi. xxv. (1860). 
Apsidoceratidje, Hyatt, 1883. 
Tripleuroceras, Hyatt. Type, Orthoceras Archiaci, Ban’ande, Syst. 
Sil. Boh. vol. ii. pi. ccli. (1868). 
Apsidoceras, Hyatt. Type, Gyroceras magnijicum, Billings, Rep. 
Prog. Geol. Surv. Canada, 1853-1856, p. 307 (1857). 
Titanoceras, Hyatt. Type, Nautilus ponderosus^ White, United 
States Geol. Sur7., Final Rep., Nebraska, Hayden, pi. iii. 
(1872). 
* Ephippioceras, Hyatt. Type, Nautilus ferratus, Cox, in Owen, Geol. 
Kentucky, vol. iii. p. 574, pi. x. (1857). 
Pteronautilus, Meek. Type, Nautilus Sehachianus, Geinitz, Dyas, 
Taf. xi. (1861). 
Trigonoceratid^, Hyatt, 1883. 
* Trigonoceras, MUoy. Tj^epOrthocera p>aradoxica, J. de C. Sowerhy, 
Min. Conch, vol. v. pi, cccclvii. (1825). 
