194 CONTRIBUTIONS TO CANADIAN PALEONTOLOGY. 



but only one of these has the lateral denticles preserved. In this lat- 

 ter sfiecimen, whose inner or convex sujface is buried in the matrix, 

 the central cusp is exceptionately long and slender, and the plications 

 at the base of its outer surface are unusually short, small and nearly 

 uniform in size. 



The detached teeth for which the present provisional name is pro- 

 posed, seem to differ from those of the L. macrorhiza, from the "Nio- 

 bi-ara epoch" of Kansas, in their proportionately broader and shorter 

 dental crowns, in their very slightly divergent and nearly hoj-seshoe- 

 shaped roots, and more particularly in the distinctly though minutely 

 plicated surface of their inner coronal faces. 



TBLEOSTBl. 



Enchodus Siiumardi, Leidy. 



Plate "26, figs. 7, 7a, 7b and 7c. 



Enchodus Shumardi, ]jeidy- 187o. Contr. Extinct Vert. Faun. W. Terr. (U.S. 

 Geol. Surv. Terr., vol. 1) p. 289, pi. 17, fig. 20. 



A small slab of shale whose fossilifei'ous surface is strewn with dis- 

 placed portions of the jaws, with the teeth in situ, and detached teeth 

 of a small species of Enrhodus, was collected by Mr. Tyrrell in 1887, 

 on the Eolling Jiiver, two miles below the old C. I'. E. crossing, from 

 the Niobrara gi-oiip or upper j^art of the sei-ies. These remains arc 

 probably referable to the E. Shumardi of Leidy, a species which was 

 based ujjon a dentary hone with teeth, found by Dv. Benjamin F. 

 Shumard in ash-coloured shalcw of the Ci-otaceoiis series of Nebraska, 

 though, judging by the description, and more especially by the figures, 

 in the fifth volume and atlas to the fifth volume of the " Poissons 

 Fossiles," it is dilHcult to see by what characters they can bo distin- 

 guished from the E. halocyon of Agassiz. 



The specimen collected bj^ Mr. Tyrrell, like the fragment desO'ibed 

 by Dr. Leidy, shows that in this sjiecies the lower jaw was armed with 

 nearly straight and erect, but very slightly incurved, slender l-eeth, 

 placed at rather distant intervals, and that these teeth are of unequal 

 size, the one nearest the .•interior end of each ramus being much longer 

 than any of the rest. Impressions of the greater part of each of the 

 dentary bones, with the teeth in place, are preserved, and the surface 

 ornamentation of part of the lower jaw is veiy well exhibited. The most 

 perfect of the dentary bones indicated in the specimen figured (fig. 7) is 

 foi'ty millimetres long and thirteen mm. broad or deep at its broken 



