Geol.— Vol. II.] ANDERSON— CRETACEOUS DEPOSITS. IO9 



forms a sort of angle. These tubercles are not generally found upon all the 

 ribs, but are often upon only alternate ones. As the growth of the shell pro- 

 ceeds, these rows become series by the development of other secondary 

 tubercules that cause a doubling or trebling of the rows. This is more par- 

 ticularly so with the external row. At the diameter of 5 or 6 centimeters, 

 these tubercules appear to reach their maximum development and form 

 almost a continuous series from the umbilicus outward, which has its greatest 

 height upon the ventral side. Above this diameter they gradually decline in 

 prominence and at the diameter of 12 centimeters they become obsolete. 

 The form of the shell also changes with age and becomes less angular and 

 more rounded in section. The suture line consists of three saddles and two 

 lateral lobes with one or two auxiliary lobes and saddles within the umbilical 

 angle. The first lateral saddle is very prominent. The saddles are broad 

 and are not deeply incised, the lobes are unequally bifid, the longer division 

 terminating in a long, narrow digit with short branches and denticles. 

 D'Orbigny's figure represents this form quite perfectly. 



The figures and description of Acanthoceras s^miferiLin'^ 

 Whiteaves agree with this species perfectly as it occurs in 

 the California beds, and the differences between the 

 Queen Charlotte Island specimen sent to Kossmat and the 

 European species seem to be unimportant. In fact, the 

 features upon which the distinction is founded do not seem 

 to be constant for either the European samples, or those 

 obtained from California. 



This shell is not uncommon at Horsetown and at Hulen 

 Creek, a few miles to the west. 



Scaphites. 



Until now the genus Scaphites has been all but unknown 

 in the Pacific border province of America, though it is well 

 represented both in the Cretaceous of Southern India and 

 in that of the upper Missouri, from either or from both of 

 which sources it may have been derived. It is therefore of 

 some interest to find at last within the limits of the West 

 Coast Cretaceous no less that six species of this shell so 

 characteristic of many marine Upper Cretaceous deposits. 



In the rich fossil beds of Southern India this genus is 

 most abundant in the lower horizon, the Ootatoor, which 

 has been correlated with the Cenomanian of Europe. In 



1 Mes. Foss., Vol. I, Pt. IV, p. 273, PI. XXXV. 



