17 



Compared with a dorsal spine* of Arius egertoni, var. belgicus, Leriche, from the Eocene 

 of Belgium, the Cypress Hills spine is much more robust above, although the proximal end and 

 the basal perforation are of about the same size in each. 



REPTILIA. 



CHELONIA. 



Anosteira ornata? Leidy. 



Plate I, figs. 17, 18 and 19. 

 Anosteira ornata, Leidy, 187] . Proc. Acad. Nat. Sci. Phila., p. 102. 



A marginal plate of a turtle from the eastern escarpment of the Cypress hills (collection 

 of 1904) bears so striking a resemblance in general form and ornamentation to those of Leidy's 

 species from the Bridger Eocene of Wyoming, that it is, for the present, referred to that 

 species. 



The plate is triangular in section, the free edge being sharp and smooth, the inner surface 

 excavated (figure 19). It is apparently the eleventh plate from the right side of the shell. 

 The sculpture beneath, fig. 18, consists of distinct, discontinuous, radiating ridges of varying 

 length with a few tubercles at the centre. The upper surface, fig, 17, is somewhat similarly, 

 but more rugosely ornamented, the tubercles here predominating ; although toward the margins 

 of the plate they tend to coalesce into short divergent ridges. A furrow across the middle 

 of the upper surface marks where contiguous epidermal shields met. This groove is continued, 

 though very faintly, on the under surface of the plate. Leidy was doubtful as to the presence 

 of shields in this species. In his description** he mentions that the shell "appears to be 

 devoid of the usual outlines more or less strongly expressed, of the investing scutes." 



A second marginal plate from the same locality bears a slightly different sculpture. The 

 upper surface is granulose throughout, without the formation of definite ridges, although the 

 tuberclbs frequently coalesce. The lower surface would be quite smooth but for an indistinct 

 granulation near the free border. The plate is wedge shaped, shallowly concave above, but 

 convex beneath, and grooved on the inner border. A sulcus also in this plate denotes the 

 presence of epidermal shields. The anterior marginals in the type are stated to be smooth 

 beneath, and it is probable that this plate belongs to that part of the shell anterior to the 

 axillary notch. 



In Bone coulee, Cypress hills, was found another specimen probably belonging to the 

 species represented by the eastern escarpment marginals. It is a lateral marginal, probably 

 the fifth of the right side, and is definitely sculptured in agreement with the type of A. ornata. 

 This specimen also bears scute impressions. 



More material is needed to more definitely determine the Cypress Hills species, which, 

 from the evidence now available, and so far as a comparison can be made, apparently very 

 closely resembles the Eocene species described by Leidy. Additional specimens, however, 

 will probably prove the Cypress Hills species to be distinct from A. ornata, bringing to light 

 a form representative of the Oligocene deposits. 



* Memoires du Musee Royal d'Histoire Naturelle de Belgique, t. III. Les Poissons Jiocenes de la Belgique, par Maurice 

 Leriche, 1905, p. 143, pi. IX, figs. 4 and 5. 



** 1873. Contr. to the Extinct Vertebrate Fauna of the Western Territories. Report U. S. Geol. Survey Terrs., vol. I. 

 p. 175, pi. XVI, figs. 1-6. 

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