120 WHITEAVES ON CEETACEOUS AMMONITES 



periphery. The suturai lines, which are well preserved in two of the specimens collected 

 by Mr. McConnell, are essentially similar to those of the Dakota specimens figured by 

 Meek. 



Mantell and Sowerby, who both figure the same specimen of Ammonites Woolgari, say 

 that it is peculiar to the Lower Chalk near Lewes, Sussex, but Sharpe states that it occurs 

 also in the Middle Chalk of that county. In his " Eeport on the Invertebrate Cretaceous 

 and Tertiary Fossils of the Upper Missouri Country " (page 45*7) Mr. Meek makes the fol- 

 lowing remarks as to the localities and geological horizon at which A. Woolgari (which 

 he regards as the type of the subgenus Prionolropis of his genus Prionoryclus) had then 

 been found in North America. " Our figured specimens are from the south-east base of 

 the Black Hills, Dakota, where it occurs in the Fort Benton group of the Upper Missouri 

 Cretaceous series. The specimens described by Prof Hall and the writer under the name 

 Ammonites percarinatus came from the same horizon on the Missouri, five miles below the 

 mouth of Vermilion River. It also occurs at this horizon in north-eastern Nebraska; and 

 I am informed by Dr. "White that he has found loose specimens of it in the Drift of north- 

 western Iowa. Dr. Newberry likewise brought specimens of it from New Mexico, and 

 Dr. Palmer found it eight miles north of Fort Lyon, Colorado. I am not aware that it 

 has been found in silu at any other horizon than that above stated, in this country." 



Mr. Meek also states that North American examples of A. Woolgari attain to "a 

 medium size," the largest specimen seen by him, " with part of the non-septate portion 

 wantino'" is seven inches in its greatest diameter. Specimens from the Athabasca district 

 vary very considerably in their dimensions, for in two of the most perfect specimens 

 collected by Mr. McConnell, both of which have most of the body chamber preserved, the 

 larger, as already stated, is fifteen inches aiid a half in its maximum diameter, and the 

 smaller only seven. 



The only other Ammonite from the Cretaceous rocks of Canada that can be referred 

 to the genus Acanthoceras with a reasonable degree of certainty, is the Ammonites Stolicz- 

 kanits of Gabb, a spinose variety of which was collected by Mr. James Richardson in 

 1872, from the Earlier Cretaceous of Skidegate Inlet, in the Queen Charlotte Islands. ' It 

 is most probable, however, that the fossil from the Cretaceous rocks of Fort St. John, on 

 the Peace River, which was described on page 239, Section IV., of the second volume of 

 the Transactions of this Society, as Buchiceras cornulum, but whose suturai line is unknown, 

 is also an Acanthoceras not very distantly allied to A. Woolgari. 



Ottawa, October 10, 1892. 



> See Geol. Surv. Canada, Mesoz. Foss., vol. I., p. 24, pi. iii., fig. 3, and pi. iv., fig. 1, also woodcut, fig. 2, on p. 24. 



