Apr. 

 1918 



STEPHEOCERAS ** 



Genus, OVATICERAS, nov. 



Type, Am. ovatus, Young & Bird 1822 (Y.T.A. CXIa) 



1 ike Harfioccratoides (Y.T.A. I, 0) but with less developed suture- 

 line the lobes being shorter and simpler; with inner margin rounded 

 off progressively flattening ; and with radial curve less bowed laterally, 

 though ultimately becoming more bowed and much more rostrate 

 Distinct from Eleganticeras (Y.T.A. II, viii) by inner margin, radial 

 line and suture-line. 



Genus, QUENSTEDTOCERAS, Hyatt 



1876, Gen. Stephanoc; Proc. Boston Soc, xvm, p. 390. 



" Quenstedioceras Leachii." No description, the name only casually 

 referred to. " Hyatt first wrote Quenstedioceras . . . this is 

 evidently a printer's mistake. The correct spelling of the name is 

 Quenstedtoceras and not Quenstedticeras," Pompeckj (Jur. Fauna ; Nor- 

 wegian North Polar Exp., II, 1899, p. 96, footnote). Hyatt obviously 

 intended -oceras not -iceras, and the original should be followed when 

 not an evident printer's error. The species referred to is Ammonites 



Leachi, J. Sowerby. 



Result 



Genus, Quenstedtoceras, Hyatt, 1876 : Type, Q. leachii, Hyatt, 

 (Am. leachi, J. Sowerby, Min. Conch., Aug. 1819, ccxlii, f. 4.). 



Genus, STEPHEOCERAS, S. Buckman 



1898, Jurassic Time; Quart. Journ. Geol. Soc. liv, pp. 454, 455. 



" This is only an alteration of the name Stephanoceras, because that 

 was pre-occupied when proposed by Waagen. The type species, how- 

 ever, remains the same — namely, Siepheoceras Humphriesianum (Sow.) " 

 (p. 454). The description then proceeds to detail the characters of the 

 Humphriesianum-group ; and ends " To one series of [what have been 

 called Stephanoceras], the Humphriesianum group, the name Siepheoceras 

 is now appended, in lieu of Stephanoceras ;" p. 455. Any doubt which 

 might arise as to the exact species of so-called " Stepheoc. Humphries- 

 ianum " which should be the type — for the description shows that the 

 name was used in a general not in a particular sense — was set at rest 

 by Mascke : he chose Am. Humphriesi[anus] Sow." as type (Stephano- 

 ceras ; Inaug. Diss. Gottingen, 1907, p. 34). 



Robert Douville, however, in 1912 (Cardioc; Mem. Soc. Geol. France, 

 xix (2), p. 28) argues that the type of the genus Stepheoceras must be 

 Am. coronatus, on the ground that this is the type indicated by the 

 etymology of Stephanoceras, that it was chosen by Henri Douville in 

 1890, and that Stepheoceras replaces Stephanoceras. But even if one were 

 to admit the first two of these premises in regard to Stephanoceras, they 

 do not affect the type of Stepheoceras. It may not have been desirable 

 to consider Am. humphriesianus as the type of Stephanoceras ; but, at 

 any rate, it was so taken. And then the name Stepheoceras was definitely 

 proposed for the Humphriesianum group with Stepheoc. Humphriesianum 



