209 



which is known to occur at Skidegate Inlet, but its sculpture appears 

 to be quite different. The surface of A. Brewerii is described as 

 " variable from nearly smooth, or marked only by sinuous striae, to 

 strongly costate. the striae assuming the character of irregular ribs, 

 most marked on or near the dorsum,"* and the ribs of the costate 

 variety figured by Mr. G-abb are invariably represented as simple. 

 Haploceras Cumshewaense appears also to be nearly related to the 

 Ammonites Kandi of Stoliczka, f which Neumayr says is an Olcoste- 

 phanus, J but in the latter species there are said to be only five periodic 

 arrests of growth in the outer whorl. 



(Section A. Nor males.') 



STEPHANOCERATID.E. 



The sutural line, the comparative size of the chamber of habitation 

 and the shape of the outer lip being unknown in all the specimens col- 

 lected of each of the four following species, it is difficult to allocate the 

 latter satisfactorily into their proper genera. From the additional 

 evidence afforded by the specimens collected by Dr. Dawson it would 

 however appear that the shells described on pages 29-32 of the pre- 

 sent volume with doubt as " Form A." and " Form B." of Ammonites 

 JJoganianus, are probably two distinct species of Stephanoceras, although 

 Drs. Neumayr and Fischer both regard that genus as confined exclu- 

 sively to rocks of Jurassic Age. The Ammonites Skidegatensis described 

 on pages 34-3*7 of this volume, seems to be a true Perisphinctes, as 

 originally supposed, although in its earliest stages it looks more like 

 a species of Olcostephanus. The type of A. Loganianus on the other 

 hand, proves to be a distorted example of an Olcostephanus (Neumayr) 

 allied to A. Astierianus d'Orbigny, which latter shell is regarded as 

 the type of his genus, although its ribs are not interrupted on the 

 periphery. 



STEPHANOOERAS OBLATUM. (N. Sp). 



Ammonites Loganianus, Whiteaves- Form A- This volume, p. 29, pi. 4, figs. 

 2 and 2a. 



This shell can no longer be regarded a variety of A. Loganianus, 



* Palaeontology of California. Vol. II., p. 130. 



t Palaeontologia Indica. Cret. Ccph. S. India, p. 140, pi. 70, figs. 4 and 5a. 



t Sitzb. dcr k. Akad. des Wissensoh, 1875, Band 71, p. 41. 



This volume p. 7, pi. 8, fig. 2. 



