392 Br. K. Woodward — Cretaceous Canadian Crustacea. 



The grorudites of Professor Brogger form the acid extreme of 

 a well-defined rock-series of which, so far as the Christiania district 

 is concerned, tinguaite is the basic extreme. No rocks answering 

 to tinguaites in chemical composition have been found in the north- 

 west of Scotland. The dykes discovered by Mr. Gunn in west 

 Eoss-shire, to which the term borolanite was extended, not without 

 hesitation, as melanite is far less abundant than in typical borolanite, 

 are composed mainly of nepheline, orthoclase, and eegirine, and 

 therefore allied to tinguaites in mineralogical composition ; but the 

 rock analyzed contains over 5 per cent, of lime — a fact which sharply 

 differentiates it from typical tinguaites. Another point which 

 differentiates these dykes from tinguaites is their structure. Nephe- 

 line, segirine, melanite, and biotite occur as idiomorphio crystals in 

 large irregular patches of orthoclase (micropoecilitic structure) 

 But if these dykes do not fit into the grorudite-tinguaite series they 

 correspond very well with some of the more basic members of the 

 plutonic mass of Cnoc na Sroine, with the nepheline - melanite 

 syenites, just as the grorudite-like rocks correspond with the more 

 acid portions of the same mass. It is probable, therefore, that 

 both are aschistic, in Professor Brogger's sense, and that they 

 represent the dyke forms of the magmas which gave rise to the 

 plutonic mass. 



In the foregoing account of this small but extremely interesting 

 petrographical province, special emphasis has been laid on its 

 relations to the Christiania district ; but it might equally well be 

 compared with other districts in which nepheline-syenites occur. 

 Jlach of these districts has its own special features. The occurrence 

 of borolanite is a peculiarity which the district in question shares, so 

 far as we know at present, only with that of Magnet Cove. 



II- — FtJETHEE Notes on Podophthalmous Crustaceans feom the 

 Uppeb, Cretaceous Formation op British Columbia, etc. 



By Henet Woodward, LL.D., F.E.S., F.G.S., etc., of the British Museum 

 (Natural History). 



(PLATES XV and XVI.) 



IN 1896 I described some decapod Crustaceans found in the 

 Cretaceous formation of Vancouver and adjacent islands, British 

 Columbia, which, with the approval of Dr. G. M. Dawson, C.M.G., 

 P.E.S., the Director, had been most kindly placed in my hands for 

 examination by Dr. J. F. Whiteaves, F.G.S., Paleontologist to the 

 Geological Survey of Canada. They were referred by me to the 

 genera Callianassa, Romolo-psis, Palfeocorystes, and Plagiolophus (see 

 Quart. Journ. Geol. Soc, 1896, vol. lii, pp. 221-228, with 6 figures). 

 From the same source I have since received a further and much 

 larger collection of specimens from the Nanaimo and Comox Group 

 (Upper Cretaceous). Like the earlier series, all these Crustaceans 

 are preserved in hard concretionary nodules, which render their 

 examination in detail often extremely difficult and disappointing, as 



