Mesozoic Floras of the Rocky Mountains. 141 



of preface to Prof. Hyatt's letter I may say that more than one 

 of the early pteropods of the St. John group are remarkable for 

 the presence of several distinct septa at the base of the tube. 

 There are two such species in the band b ; another, but a loDger 

 and narrower kind, is found in the band c, and this or a similar 

 camerated shell occurs in the band d. Of these species (refer- 

 ring, however, chiefly to the latest) Prof. Hyatt says (February 

 3, 1885) : 



" I kept no notes of the details I had observed; my results, 

 however, were quite definite in respect to the main points. These 

 were : (1) The fossil is a Hyolithes allied to _Z?, undulatus, Barr. 

 (Syst. Silur. pi. 11, f. 29.) (2) The aspect of a siphon is due to 

 the compression of the sharper against the flatter side, and the 

 form of the sutures, which favors this impression. Barrande 

 figures, as I found after arriving at this decision, a similar case, 

 (pi. 15, figs. 35, 35&) of a closely allied species, JEL. elegans. (3) 

 The sutures are similar to those of H. elegans in curvature, but 

 wider apart. These fossils with their distinct septa are startlingly 

 similar to certain forms of Nautiloidea, but there is no siphon. 

 They, however confirm Yon Jhernig's and my opinion that the 

 Orthoceratites and Pteropods have had a common, but as yet 

 undiscovered, ancestor in ancient times. " 



III. The Mesozoic Floras of the Eocky Mountain 

 Begion of Canada* 



By Sir William Dawson. 

 In a previous memoir, published in the Transactions of the 

 Boyal Society of Canada, Vol. I, the author had noticed a 

 lower Cretaceous flora consisting wholly of pines and cycads occur- 

 ring in the Queen Charlotte Islands, and had described a dico- 

 tyledonous flora of middle Cretaceous age from the country 

 adjacent to the Peace Biver, and also the rich upper Cretaceous 

 flora of the coal formation of Vancouver Island — comparing 

 these with the flora of the Laramie series of the Northwest 

 Territory, which he believed to constitute a transition group con- 

 necting the upper Cretaceous with the Eocene tertiary. 



♦Abstract of a paper read before the Royal Society of Canada, May, 1885. 



