82 FOSSIL TURTLES OF NORTH AMERICA. 



This species differs from B. arenosa in the form of the anterior vertebral scute and in 

 having no accessory lateral scute. In these respects it agrees with B. dara. From the latter it 

 differs in having the shell broader behind, a wider and more deeply scallopt postero-lateral 

 border, higher lateral marginal scutes, a different arrangement of the most anterior marginal 

 scutes, and narrower plastral lobes. The bridge of the plastron is also wider. It measures 

 160 mm., while that of the type of B. dara is only 150 mm. The bridge of B. arenosa, No. 1115, 

 a larger shell, also measures only 150 mm. On the under side of the postero-lateral border of 

 the shell, at the fifth scallop, the distance from the line where the soft skin of the animal began 

 to the outer edge of the shell is 40 mm.; in B. dara this space is only 33 mm. 



There is in the American Museum's collection a second specimen of this species from the 

 same level. It is somewhat smaller, with a total length of 323 mm., and is less perfect than the 

 one which has furnisht the above description. Nevertheless, the principal characters distin- 

 guishing the species from the others are exhibited. Altho smaller, the sutures have almost 

 wholly disappeared, so that it furnishes no aid in tracing these. 



In the collection of Princeton University there is a somewhat damaged shell which is 

 referred to this species. The catalog number is 1 1263. It was collected by Mr. J. B. Hatcher, 

 in 1895, in the Uinta Eocene, at Kennedy's Hole, Utah. The beds contained remains of 

 Dolichorhinus cornutus. 



Genus EUBAENA nov. 



Skull resembling that of Baena, but with the temporal region less extensively rooft over, 

 the squamosals not coming into contact with the parietals. Jugals excluded from the rims of 

 the orbits. Triturating surfaces of the maxillae transversely broad and concave. Choanae 

 opening between the orbits, and at nearly one-third the distance from the snout to the occipital 

 condyle. Shell unknown. 



Type : Eubaena cephalica Hay. 



Eubaena cephalica Hay. 

 Plate 19, fig. 4; plate 21, figs, i, 2. 

 Baena cephalica, HAY, Amer. Jour. Sci. (4), XVIH, 1904, p. 263, plate xii, figs. 1-3. 



The name Eubaena cephalica is given to a fine skull which is in Yale University Museum. 

 This skull, which lacks only the lower jaw, was collected in the Laramie deposits of Converse 

 County, Wyoming, by Professor J. B. Hatcher, then employed by Professor O. C. Marsh. The 

 specimen bears Professor Marsh's receipt number 21 10. 



In general form the skull is broad behind, rather flat above, and with pointed snout. The 

 length from the snout to the occipital condyle is 67 mm.; to the end of the supraoccipital 

 spine, 74 mm. The greatest breadth, just in front of the tympanic chamber, is 65 mm. From 

 these chambers the width diminishes to the snout. The flat upper surface of the skull descends 

 each way to the perpendicular sides. The sides of the face about the orbits look upward and 

 outward, as well as forward. The tympanic opening is nearly circular, 19 mm. in its perpen- 

 dicular, 15 mm. in its horizontal axis. The orbit is circular and small, its diameter beingi4mm. 

 The interorbital space is 25 mm. wide. The nasal opening, as seen from in front, is somewhat 

 heart-shaped, and is directed above and forward. From the orbit to the tympanic opening; is 

 24 mm. ; from the nares to the orbit is 10 mm. 



The temporal region is rooft over, but not so extensively as in species of Baena from the 

 Bridger beds. On each side of the supraoccipital this roof is excavated as far as a line joining 

 the anterior borders of the tympanic chambers. From the orbit to the bottom of the excava- 

 tion is 22 mm. The hinder end of the postfrontal is interposed between the parietal and the 

 squamosal. 



In general, the sutures of the skull are very distinct, but no trace has been found of those 

 between the frontals and the parietals. There are distinct nasals, and these and the prefrontals 

 resemble closely the same bones in the Bridger species of Baenidae. The prefrontal of each 

 side joins the postfrontal, so that the area of the frontal is excluded from the border of the orbit. 

 The sagittal suture extends from the prefrontals to the supraoccipital spine, a distance of 



