22 The Ottawa Naturalist. [May 



some volcanic rocks of mes ozoic age on the Iltasyouco River and 

 Tigutlat or Tsehouts Lake, in the coast range of British Col- 

 umbia. These fossils were reported on by the writer in 1878, in 

 the Report of Progress of the Geological Survev for 1876-7 7, in 

 which the Ammonites were determined by Professor Hyatt. 

 Among them there is an Ammonite from Tigutlat Lake that 

 Hyatt referred to Stephanoceras H umphreysianum, and that 

 the writer identified with Olcostephanus LoganianMS of the Queen 

 Charlotte Islands in 1884, and figured under that name on Plate 

 XXIII, fig. 1 , of the first volume of " Mesozoic Fossils " published 

 by the Canadian Survey. It has long been obvious, however, 

 that this Ammonite can no longer be safelv identified with either 

 of the species named, and it would now seem that it probably 

 indicates a previously unnamed species of Stepheoceras, which 

 it will be convenient to designate as 5. Pluto. It seems to differ 

 from the typical O. Loganianus chiefly in its much wider and 

 more open umbilicus. 



On the evidence of specimens recently collected in Alaska, 

 Dr. Stanton regards the two species of Ammonite from the Queen 

 Charlotte Islands which the writer described and figured in the 

 first volume of "Mesozoic Fossils "under the names Perisphinctes 

 Carlottensis and Olcostephanus Loganianus, as of Jurassic rather 

 than Cretaceous age, and refers them both to Stephanoceras, 

 Waagen.* If this view be correct these two species, also, may 

 possibly be referable to Stepheoceras, but the sutural line of both 

 is unknown, and their exact generic position is still uncertain. 



In August, 1904, Dr. R. W. Ells and Mr. R. A. A. Johnston, 

 of the Geological Survey staff, collected a few specimens of a 

 large Ammonite, which is by far the most typical and distinct 

 species of Stepheoceras that has yet been found in Canada, from 

 a small outlier of compact and readily weathering limestone on 

 the side of a mountain about a mile and a half north of a point 

 in the road midway between Nicola and Coutlee, in the Yale 

 district of British Columbia. 



These specimens are two casts of the interior of most of 

 the septate portion of the shell, and eight fraginents. 



The larger of these two casts was originally about eighteen 

 or nineteen inches in its maximum diameter, but a piece of the 

 anterior end of it has been mislaid, and the specimen is now only 

 fourteen inches across. 



The smaller cast is about eight inches in its greatest diameter, 

 and has most of the two outer whorls exposed on one side. 



Neither of these casts show any evidence of septation, but 



* In Bulletin of the Geological Society of America, June, 1905, vol. 

 16, p. 402. 



