18 ART. 2. H. Y ABE I CRETACEOUS 



Forbes Ammonites Budha. The single fragment of an Ammonite 

 from the Hokkaido shows the character of the subgroup. 



VI. Subgroup of Gmidryceras varuna Forbes sp. 



This subgroup hokls a somewhat isolated position as compared 

 with the above five, including G. varuna Forbes sp.,^^ G. odiense 

 KossMAT sp.,"' G. anaspatnm Redtenbacher sp.'^^ and G. Kawanoi 

 JiMBö sp.^' The whorls of these species are considerably compressed 

 on the side, the involution being very deep and the umbilicus 

 narrow from the beginning of the shell, while the surface is 

 nearly smooth. To these differences is still to be added another 

 concerning the course of the suture line. There are numerous 

 auxiliary lobes slowly diminishing in size toward the umbilicus. 



Although it appears somewhat artificial to make such sub- 

 divisions of Gaudryccras as above enumerated, yet in this way, 

 not only geologically younger forms are easily separated from the 

 older, but also the extreme confusion which has hitherto prevailed 

 among the Ammonites of the whole group may also be avoided. 



1) Kopsmat: I. c. p. 34 (130); p. 65 (Ifil), PI. II (XYI), figs. 4 a, h ; PI. Ill (XYII), 

 fig. 8. 



2) Kossmat: ]. c. p. 33 (129), PL IV (XVIIH, fig. 1 a, h, c ; PI. V (XIX), fig. 3. 



3) Rebtenbacher : 1. o. p. 113, I'l. XXVI. fig. 1. 



4) Vide p. 41. 



