14 



The vertebral centrum is from about the middle of the dorsal series, and is long in pto- 

 portion to its breadth and height. In end view the articular surfaces are six-sided, the 

 anterior surface k slightly convex : the posterior one as slightly concave. The parapophyses 

 are given off at* the mid-height of the centrum a little in advance of the mid-length, j9, fig. 9. 

 Beneath each parapophysis is a deep fossa, long in an antero-posterior direction, occupying 

 the lateral inferior face of the centruni and separated from its fellow by the narrow, flat 

 inferior surface which is broadest at either end, where it is also most deeply impressed by a 

 longitudinal median groove. The surface between the parapophyses and the neurapophyses, 

 n, fig. 7, is deeply eycavated. The floor of the neural canal channels the upper surface of 

 the centrum, the depression being greatest at mid-length. There is also a small fossa above, 

 a little behind the parapophyses. The surface of the centrum throughout is quite smooth. 



A conspicuous character of the above centrum is" its length as compared with its height 

 and breadth ; length of centrum, along median line, inferiorly, 10 mm. ; height of posterior 

 articular face, 6'8 mm. ; breadth of same, 83 mm. 



The name longu's is here made use of for the fossil gar represented by the Cypress 

 Hills specimen. 



EhINEASTES RHiEAS. 



Plate I, figs. 10-16. 



Rhineastes rhceas, Cope, 1891. The species from the Oligocene or Lower Miocene beds of the 

 Cypress hills. Geol. Survey of Canada, Contr. to Can. Palfeont., vol. Ill (quarto), pt. I, 

 p. 3, pi. I, figs. 3, 3a and 36. 



A few broken vertebrae are apparently referable to this species. In comparison with the 

 type material, the internal structure of the centrum in the present specimens is seen to be the 

 same, viz., close set vertical laminae parallel to the articular surfaces. 



The vertebrae mentioned in the original description of the species consist of a median 

 abdominal vertebra (the type spec.men), and a second centrum that is referred by Cope to this 

 species not without some doubt. There is with this material a third vertebra, not mentioned 

 by Professor Cope, and possibly not seen by him, which is slightly larger, and more perfect than 

 the type. This specimen, with little doubt, belongs to this species, but calls for remark in that 

 it is definitely flattened below, and is without a fossa beneath the base of the diapophysis. 

 In the type the inferior surface is broken away. 



In the 1904 collection are a number of bases of pectoral spines, serrated on both the 

 anterior and posterior borders, probably referable to Ehineastes rhceas. In the genus Amiurus, 

 to which the other Siluroid remains in the collection belong, the pectoral spine is serrated on 

 the posterior border only, whilst in Rhineastes this spine may be serrated on one or both 

 borders. 



All the pectoral spines are imperfect distally, and show a considerable range in size. 

 One of the most perfect is small, but gives the details of ornamentation well. The sides are 

 covered with low narrow longitudinal ridges which often inosculate. There is no sign of 

 tuberculation here; such as is found in conjunction with longitudinal ridges on the spines 

 oi Arius egertoni oi X\i& middle Eocene of England, and Belgium. On the anterior border 

 there is a median serrated ridge bounded on either side by a well-marked narrow groove. 



