[From the Quarirrly Journal of the Geological SociEiir/oi- ^-^ 



Fehruarij 1879.] j 



Oil a NEW Species of Loftusia from British Columbia. By 

 George M. Dawson, D.8., Assoc.ll.S.M., F.G.S., of the Geo- 

 logical Survey of Canada. 



[Plate VL] 



L\ 18G9, Dr. W. B. Carpenter and Mr. H. B. Brady described, iu the 

 'Transactions ' of the lloyol Society, two remarkable types of gigantic 

 arenaceous Foraminifera, under the generic names of ParJceria and 

 Loftusia. For the description of the latter form Mr. Brady is more 

 particularly responsible, and tot!-.. ;?enus then created by him I have 

 now to add another species, for which the name of Loftusia Colum- 

 biana is proposed. 



The original specimens of Loftusia were obtained many years ago 

 by Mr. W. K. Loftus in Persia. They were referred to in "his paper 

 on the geology of the Turco-Persian frontier and districts adjoining, 

 published in the Quarterly Journal of the Geological Society in 1855, 

 but remain w'd undescribed till they came into Mr. Brady's hands. 

 From the geological descriptions by Mr. Loftus, and other forms of 

 Foraminifera found in the same stones, Mr. Brady believes the geo- 

 logical position of Loftusia persica to be in the oldest Tertiary rocks. 

 The specimens now to be described are from the interior of British 

 Columbia, and their ago is, I believe, Carboniferous. Examples of 

 the form were first collected by Mr. J. llichardson, of the Geological 

 Survey of Canada, in 1871, and are mentioned in the Eeport of 

 Progress for 1871-72. About a year ago, I examined Mr. Ilichard- 

 son's specimens with some care ; but during the past summer, having 

 opportunity to visit the locality from which they were procured, the 

 occasion was taken to collect a large number of additional specimens, 

 representing all varieties of appearance and preservation. Mr. 

 Thomas C. Weston has prepared from these and JMr. Richardson's 

 specimens a number of transparent sections, from which the accom- 

 panying descriptions and drawings have been made. 



Most of the specimens are from Marble Caiion, a remarkable valley 

 which runs through from the banks of the Fraser Eiver to the bend 

 of Hat Creek, with a direction nearly transverse to that of the main 

 features of the country. For a distance over ten miles, the sides of 

 the vaUey are formed almost continuously of mountains of limestone 

 or marble. The first impression is that an immense thickness of 

 limestone is represented in the exposures; but, although the dips are too 

 obscure to allow the attitude of the beds to be worked out throughout 

 the length of the Canon, some small sections show that part at least 

 of the beds have been sharply folded and the whole series of folds 

 overturned. This being the case, it may be that a comparatively 

 thin limestone or series of limestones forming a succession of folds 

 superimposed on a broad anticlinal flexure account for the appear- 

 ance presented. That the limestones have a very considerable thick- 



