WHITEAVES.] CRETAOEOOS FOSSILS FROM BRITISH COLUMBIA. 157 



the small siphonal saddle. The first lateral lobe is much larger than 

 any of the rest and is rather deeply and unequally divided a little on 

 one side of the centre by a small offset of the first lateral saddle. All 

 the lobes are incised at their margins, but the siphonal and first lateral 

 lobes are the only ones that are branched. 



In 1876, the writer, who had not then seen a copy of Dr. Neumayr's 

 paper on the Ammonites of the Chalk Formation,* expressed the 

 opinion that the type of the present species belongs to the group of 

 the Clypeiformes and that it might prove to be an Oppelia allied to the 

 0. Waager.i of Zittel. 



A subsequent study of other specimens from the Queen Charlotte 

 Islands, in 1884, induced the writer to refer the species to Haploceras, 

 on account of its supposed affinities with the Ammonites Oleon of 

 d'Orbigny and A. bicurvatus of Michelin, both of which were placed by 

 Dr. Neumayr in that genus. But, in his Manuel de Conchyliologie, 

 published at intervals between 1880 and 1887, Dr. Paul Fischer states 

 that the genus Haploceras, which he regards as a synonym of 

 Ziissoceras, Bayle, corresponds to the group Ligati, and places the 

 whole of the Clypeiformes in Meek's genus Svhenodiscus. 



In the second volume of the " Handbuch der Pala3ontologie " 

 (1881-85), Zittel re-defines and slightly extends the characters of 

 Meek's genus Placenticeras so as to make it embrace the whole of the 

 Clypeiformes and among the representative species cites the Ammonites 

 bicurvatus of the "Terrains Cretac^s," which, Pictet says, includes A. 

 Clean. He (Zittel) restricts the use of the generic term Haploceras so 

 as to make it include a few Jurassic and two Neocomian species, and 

 constitutes a new genus, which he calls Desmoceras, for the reception 

 of the Ligati, 



The present species, no doubt, bears a very close resemblance to 

 Desmoceras Beudanti in the general shape of its shell, and in its sutural 

 line, but differs therefrom in the total absence of the distant, periodic 

 arrests of growth which are generally held to be characteristic of the 

 Ligati. Hence it would seem that the former species can no longer 

 be satisfactorily referred to Haploceras, or even to Desmoceras, but that 

 it belongs to an aberrant section of the Clypeiformes, in which the 

 periphery or abdominal region is more or less narrowly rounded 

 rather than thin and sharp. 



By Dr. Fischer the Clypeiformes, as a whole, are included in 

 Sphenodiscus and by Zittel in Placenticeras. But, if th e specimens of 

 the present species collected by Messrs. Eichardson and McConnell 



•Uber Kreideammonitidoa. Aus dem LXXI Bande der Sitzb. der K. Akad. der Wissensoh., 1 

 Abth. Mai-Heft, Jahrg. ISTS. 



