ryTRODTJCTIOX. 
IX 
memoir. I should add that Gonioceraiidce (Hyatt), containing the 
one genus Gonioceras, is omitted, as it was dealt with in Part I. 
(Suppl. p. 322). Hyatt places the Gonioceratidce between Eudo- 
ceratidce and A^sidoceratidce, 
Taixoceratid^, Hyatt, 1883. 
*TrochoIites, Conrad. Type, T. ammonius, Conrad, Ann. Geol. Rep. 
p. 119 (1838). {Fide Hall, Pal. New York, vol. i. p. 192 (1817).) 
Pleetoceras, Hyatt. Type, Xautilus Jason, Billings, Canadian Natu- 
ralist and Geologist, vol. iv. p. 461 (1859). 
Litoceras, Hyatt. Type, Xautilus versutus, Billings, Palreoz. Foss. 
voL i. p. 259 (1865). 
Diadiploceras, Hyatt. Type, D. quadratum, Hall (apparently not 
described) ; or ?Discites inopinatus, HaU, Pal. New York, vol. v. 
pt. ii. pi. cx. (1879). 
Metacoceras, Hyatt. Type, Xautilus Sangamonensis, Meek and 'SYor- 
then, Geol. Surv. Illinois, vol. ii. pi. xxix. (1866). 
Tainoceras, Hyatt. Type, Xaidilus quadrangulus, McChesney, 
Trans. Chicago Acad. vol. i. pi. iii. figs. 5-7 (1866). 
b Hyatt. Type, Temnocheilus Mojsisovics, 
Mediterr. Triasprov. pi. Ixxxviii. (1882). 
Gnjpoceras, Hyatt. Type, Xautilus mesodiscus, Hauer, Ceph. des 
Salzkammergiites, Taf. x. figs. 4-6 (1816). 
*Clydonautilus, Mojsisovics. Type, C.\ Xoricus, ^Mojsisovics, Medi- 
terr. Triasprov. p. 281 (1882 ). 
Enclimatoceras, Hyatt. Type, Xautilus Ulrichi, AVhite, Bull. 
United States Geol. Surv. vol. i. no. 1, pis. vii., viii., ix. 
(1881). ^ 
*IIercoglossa, Conrad. Type, Xautilus orhiculatus, Tuomey, Proceed. 
Acad. Nat. Sci. Phiiadelphia, p. 167 (1855). 
*Aturia, Bronn. T^-pe, Xautilus Aturi, Basterot, Descrip, des Coq. 
Foss, des Environs de Bordeaux, Mem. Soc. dTIist. Nat. de 
Paris, vol. ii. pt. i. p. 17 (1825). 
Hercoceratidje, Hyatt, 1883. 
Plgssoccras, Hyatt. Cgrtoceras alicnum, Barr. Syst. Sil. Boh. vol. ii. 
pi. cxxvii. (1866). 
* Ilercoceras, Barrande. Type, II. mirum, Barr. Syst. Sil. Boh. vol. ii. 
pi. xlii. (1865). 
Anomaloceras, Hyatt. Type, Xautilus anomalus, Barr. Syst. Sil. 
Boh. vol. ii. pi. xxxiv. (1865). 
^Temnocheilus, M‘Coy. Type, T. coronatus, M^Coy, Synop. Carb. Foss. 
Ireland, pi. iv. fig. 15 (1841). 
*Centroceras, Hyatt. Type, Xautilus {Discites) Marcellensis, Hall, 
Pal. New York, vol. v. pt. ii. pis. Ixv., cix. (1879). 
^ Altered to Mojsisoceras by Dr. K. A. Zittel, Handbuch der Palaeontologie, 
Band i. Abth. ii. Lief. iii. p. 381. 
