4 AllT. 2. — H. YA13E : CRETACEOUS 



111 the study of the Cretaceous Cephalopodii, one of the most 

 difficult tasks is to deHue the exact limits of the diifeient genera 

 established ou the turreted forms of Ammonites. Hyatt's classi- 

 fication by creation of many new genera may possibly be an 

 improvement to the previously existing ones but it cannot Ije 

 followed here, for the generic diagnoses and discussions on the 

 taxonomy are not yet published. Therefore, the j^resent writer 

 is obliged to follow the old and well known classification of 

 D'Orbigny as modified by Sharfe and Stoliczka tliuugh it is 

 apparently unnatural. Yet, it is quite necessary to create a new 

 genus, as there is one specimen which entirely diifers frum the 

 known types in the develojmient of its shell. 



The group Turriliies, in its most comprehensive sense, foi'ins 

 a rather inconspicuous element in our fauna. Notwithstanding 

 their display of various modifications in the upper Ammonite- 

 beds, specimens are rare in all the localities, so that the descrip- 

 tion of several species of them must be left imperfect. Besides 

 those from the upper Ammonite-beds, two species of the Ceno- 

 manian ty[)es are also described below. These the writer considers 

 as specially important, for the fauna of the lower horizons is 

 very poor. 



TURRILITES cfr. BERGERI Jîrongniakt. 

 PL HI., fig. 1. 



1902. Turrilites cfr. 3Iantelli Yabe : List Cret. Amm. Hok- 

 kaido in the Outline of the (leology of Japan. 2"'^ Edi- 

 tion. rJ02. 



