CEPHALOPODA FßOM THE HOKKAIDO. 11 



The present species is distinguislied from Lytocercis Mahadeva 

 SrojLiczKA found in the lower division of the Utatur group of 

 Marattur, South India/^ and from L. Batesii ]\Ieek of the Shasta 

 group of CaHfornia and Richardson's C horizon of the Cretaceous 

 of Queen Charlotte Islands,"^ by its whorls more rapidly increasing 

 in height and breadth. 



Localities : — The Pombets and Ponporonai, tributaries of the 

 Ikushumbets, Prov. Ishikari. 



Horizon : — Lower Ammonite-beds. 



LYTOCERAS IMPERIALE m. 



PI. IL ßg! 1 ; pl. IV. %. 1. 



Among numerous specimens of Ammonites from the Cretaceous 

 of the Hokkaido which are yet undescribed, the present is the 

 most striking on account of its peculiar sculpture. The fulluwing 

 are the dimensions of the shell as actually measured in our only 

 specimen"^ : — 



Diameter. 



Height of the last whorl. 



Breadth of the last whorl. 



Width of umbilicus. 



1) Stoliczka: I.e. p. 1G5, PI. LXXX. Kossmat : I.e. p. 16 (112). 



•2) W. M. Gabb: PuUeontology of California: Creta. Foss., p. 67. PI. XIU, fig. IG a, 

 1). — J. F. Whiteaves: Mesozoie Fossils. Vol. I. Pt. 1, p. 45, PI. IX. fig. 2. Vol. I. Pt. ;>, 

 p. 202, PI. XXVII. fig. 1.— T. AV. Staxtox and Diller: The Shasta-Chieo Series. Bull. 

 Ueol. Soc. America. Vol. V. 1894. P. 446. — T. W. Staxton : Contribution to the Cretaceous 

 Puhxiontology of the Pacific Coast : The Fauna of tlie Knoxville Petls. Bull. U. S. Geol. 

 Surv. No. 133. 1895. P. 75. PI. XIII. figs 9—11. 



3) The flattening of the body-whorl, wliicli is at fii'st nearly round, does not seem to 

 be wholly due to meelianical action. It is, therefore, to be considered as one of the distin- 

 guisldng characters of the species. 



