176 PROCEEDINGS OF THE ACADEMY OP 



Fossil. Tiger. 



Breadth of crown 15| lines. 18 lines. 



Depth at anterior lobe 7 " 7J " 



" at principal cusp 9 " 9 " 



" of posterior lobe G^ " 7 " 



Width at antero-internal abutment 72 " 8j " 



Canis. 



An upper lateral incisor, impregnated with bitumen. The tooth is unworn, 

 and is intermediate in size with those of Cnnis occ.iderttalis and C. latrans. The 

 unworn crown is Q\ lines long, its antero-posterior diameter 3i^ lines; its 

 transverse diameter 3 lines. The compressed fang, broken at the end, has 

 been about 13 lines long ; its width is 4^ lines ; its thickness 2| lines. 

 Undetermined. 



An ungual plialanx, apparently of an edentate animal. The end is broken 

 off, and the specimen is thoroughly imbued with bitumen. The length is 

 uncertain, for we cannot determine whether it was blunt or pointed at the end. 

 Supposing it to have been in the former condition, it has been about 28 lines 

 long. The breadth is more than half the length, and is much greater than the 

 depth or thickness. The bone is without sheath, transversely oval in section, 

 13^ lines wide by 10 lines in depth. The articular facet forms a trochlear 

 concavity, with vertical median elevation, and is directed backward and down- 

 ward. About one-fourth of the length from the base it expands, and then 

 gradually narrows forward to the apex. The upper surface forms an inclined 

 jilane forward, and is convex transversely, and smooth. Its greatest width 

 just back of the middle is 16 lines. The under surface is convex transversely, 

 and slightly so in the length. On each side of this surface, just in advance of 

 base, there is a large vasculoneural foramen, penetrating to the interior of the 

 bone. A wide but shallow groove curves forward between the foramina, and 

 a deeper one diverges from each laterally and backward. The lateral borders 

 of the ungual expansion are obtuse. 

 Undetermined. 



A bone of uncertain character, but resembling a phalanx. Slightly impreg- 

 nated with bitumen. It is a curved, four- sided pyramid, with a square plane 

 base, truncated deeply at one angle. A strong boss occupies the incurvature 

 of the bone at the base, and at the side of the truncated angle. The border of 

 the pyramid along the convexity opposite the latter is likewise truncated. The 

 bone in the structure of its surface looks as if it might be of reptilian charac- 

 ter, exhibiting everywhere a rather conspicuous vascular porosity. The 

 length of the specimen in the axis is 16 lines, the diameter of the base 11 by 

 10^ lines. 



Emydes. 



Small fragments of the carapace and sternum of several species of emydes, 

 thoroughly imbued with bitumen. Most of the fragments are too imperfect to 

 characterize the species, but some of them indicate an animal about the size of 

 the living Einys scabra of the southern States, but evidently a different species, 

 as the bones are proportionate!)' much more robust. The fore part of the ster- 

 num differs from that of E. scabra in the abrupt projection forward of the inner 

 division of the episternals. A pair of these together at the articulation of the 

 hyposternals give a breadth of 43 lines ; depth of tlie episternals to the ento- 

 sternal 13 lines; projection forward of the part covered by the gular plates 4 

 lines ; greatest thickness 5^ lines. A hyposternal about its middle is 28 lines 

 from before backward ; 26 lines in width behind the inguinal notch; and 6 

 lines where thickest internally. The fore part of a nuchal plate resembles the 

 corres[)onding portion in E. scabra. but is more deeple indented. Its width 

 anteriorly is an inch ; the length of its median column lOj lines ; its thickness 

 where greatest 6 lines. The species may be distinguished by the name of 



E.MYS PETROLEI, 



Probably belonging to the subgenus Trachemys of Agassiz, like Emijs scabra. 



[June, 



