vi YORKSHIRE TYPE AMMONITES Mar. 



191 1 



Genus, CORONICERAS, Hyatt, 1867 



1867, Foss. Ceph. ; Bull. Mus. Comp. Zool., V, 77. 



The genoholotype is definitely indicated by the name — Coroniceras 

 for Am. coronaries, for which is cited Quenstedt, Jura, vii, 5. 



Result 



Genus, Coroniceras, Hyatt, 1867. Genoholotype, Am. coronaries, 

 Quenstedt. 



Genus, ARNIOCERAS, Agassiz-Hyatt, 1867 



1867, Foss. Ceph. ; Bull. Mus. Comp. Zool., V, 73. 



The type is definitely indicated (i) by the generic name, (2) by the 

 species credited to Agassiz. 



Arnioceras {apvftSs, a ram) indicates a type with trivial name ceras 

 or similar ; and Agassiz's name appears after Ar. ceratitoides — Arnioceras 

 being one of the five genera which he selected (Hyatt, 71). 



Under Ar. ceratitoides are three references — A. ceratitoides, Quenstedt, 

 A. ceras, Giebel, and Hauer. In Gen. Ariet. Hyatt places the first to Ar. 

 bodleyi, the other to A. ceras, Agassiz. On this evidence it seems desirable 

 to select Ar. ceras figured in Gen. Ariet. 11, 20. 



Result 



Genus Arnioceras, Agassiz-Hyatt, 1867. Type, Ar. ceratitoides, 

 Agassiz, of which Ar. ceras, Agassiz (Hyatt, Gen. Ariet. 11, 20) is geno- 

 lectotype. 



Genus, ARIETITES, Waagen, 1869 



1869, Form. Am. subradiatus ; Geogn.-Pal. Beitr. II (2) 246. 



This genus was proposed for the family of Arietes ; and Waagen 

 mentions Ar. hucklandi, Sow. as the most noted representative. It is 

 almost certain, however, that he had not correctly identified Sowerby's 

 species, as his definition does not agree in many points. 



S. Buckman (Quart. J. Geol. Soc, 1898, LIV, 452) proposed to take 

 A. turneri, J. de C. Sowerby, as type of Arietites. This species fulfils 

 Waagen's definition very well, especially having the " long pointed 

 process on the venter." This particularly distinguishes the series from 

 Asteroceras, where the process is short. In A. bucklandi the process is 

 comparatively short. 



A. turneri, A. hrooki, Sow., A. denotatus Simpson (A . collenottii ; 

 Wright, XXII b), A. fowleri, J. Buckman {A. denotatus ; Wright, vi, i) are 

 some of the species which belong here. 



Result 



Genus, Arietites, Waagen, 1869. Type, one of the Arietes ; 

 genolectotype, A. turneri, J. de C. Sowerby, ccccLii, upper figure. 



