328 CONTRIBUTIONS TO CANADIAN PALEONTOLOGY. 



islands and on a small island off Weston Point, at Point Brabant, on 

 the west side of Cameron Bay, and at a few exposures on the shores and 

 islands of Dawson Bay ; also, on the Red Deer Kiver at or near the Lower 

 Salt Spring. At each of these localities it was obtained in more or less 

 abundance by Messrs. Tyrrell, Dowling and the present writer in 1888 

 and 1889. 



Most of the specimens from the Stringocephalus zone are natural moulds 

 of the exterior of the shell, with the surface characters fairly well pre- 

 served, and it is from wax impressions of several of these moulds (two of 

 which are figured) and from two small testiferous examples, that the fore- 

 going description was made. The specimens from the limestone immedi- 

 ately above the Stringocephalus zone, on the other hand, are mere casts 

 of the interior of the shell, most of which are very badly preserved, together 

 with a few opercula, and it was upon these easts and opercula that the 

 description and figures of EnompliaJ us J\/(i iiitob>' ns I n were based. One of 

 these casts is so broken as to show the operculum in situ, though a little 

 displaced from its natural position, but none of them show the cliaracters 

 of the lower side at all well. Befoie these angulated and nodose moulds 

 of the exterior of tlieshell wei'e very critically studied, they were regarded 

 by the writer as not only specifically but also subgenei'icallj' distinct fi'om 

 the comparatively rounded, smooth and frequently depressed internal casts 

 foi' which the name S. j\fuiiitohe}isifi was proposed, but they are now all 

 regarded as diiTerent states of pi'eservation of a single species of Oiiip/ia- 

 lorArniK. The angulation and peculiar tuberculation of the outer volution, 

 as seen in moulds of the exterior oi' in testiferous sjiecimens, is obviously 

 caused by a thickening and plication of the outer layer of the test and 

 does not affect the iunei' layer, while the depression of many of the internal 

 oasts, especially that of the type of JE. Miinitohiviixin figui'ed in the Tran- 

 sactions of the Royal Society (jf Canada, is evidently abnormal, as the 

 operculum shows that the aperture must/ have been circular in outline 

 when undistorted. 



The type of the genus OmpJia!(>ri.r)-iis of De Ryckholt (1860) is the 

 Eaomp/iahis Goldfiissiot d'Archiac and de Verncuil,but in that species the 

 outer volution is angulated and tuberculated on one side imly, and the 

 whole shell is more tleeply concave above than below. According to 

 Fischer*, Coelocentrus, Zittel (1882) is a synonym of Oiiipha/orirrKs. 



(S.) Straparollina obtusa. (^N. Sp.) 



Plate 42, figs, 12, 12a and 13. 



Shell turbinated, somewhat conical, its height a little greater than its 

 maximum breadth : spire elevated, rather higher than the outer volution, 



"Manuel de Conohyliologie, Paris, p. .S2!l. 



