No. 1747. DESCRIPTIONS OF Y/.'U FOSSIL TURTLES- HAY. 313 



the left in the other. The abdomino-femoral sulcus runs straight 

 across the hypoplastra from opposite the middle of the inguinal but- 

 tresses, thus differing considerably from that of C. parva. 



On the right mesoplastron and hypoplastron the lower surface is 

 mostly furnished with small pits and low ridges, but there are areas 

 where these are replaced by pustules. Especially near the sutural 

 borders the pustules are arranged in rows at right angles with the 

 suture. The left hypoplastron is everywhere ornamented with pus- 

 tules and this is doubtless the normal condition. The pustules have 

 the size and flatness seen on the bones of the type specimen. 



The sculpture of this species differs from that of both C. victa and 

 C. parva. The neural of C. victa, the second, fourth, or possibly 

 sixth, is 24 mm. long, 25 mm. wide, and 9 mm. thick. The third 

 neural of 0. vafer is only 8 mm. thick. It is greatly to be desired that 

 more complete specimens of C. victa be collected in the type-locality. 



BASILEMYS PR^ECLARA, new species. 



The remains on which this species is based were found on June 21, 

 1909, by a party of the U. S. Geological Survey consisting of Dr. 

 T. W. Stanton, Mr. M. R. Campbell, and Mr. W. R. Calvert. The 

 bones are accompanied by a note which states that they were found 

 in the so-called somber beds, about 3 miles northeast of the mouth 

 of Dirt Lodge Creek, South Dakota. The more accurate locality is 

 given as section 12, township 20 north, range 22 east. This is in 

 Boreman County, north of Grand River. In the same collection are 

 bones of Trachodon, Triceratops, Myledaphus bipartitus, and other 

 fossils belonging to the Lance formation, better known as (Vratops 

 beds. The specimen consists of the epiplastral beak, a fragment of 

 the rim of the posterior lobe of the plastron, the thickened anterior 

 border of the nuchal, a free peripheral bone, and a number of frag- 

 ments of the plastron and the carapace. The catalogue number of 

 the specimen in the U. S. National Museum is 6540. 



The most important part of the turtle here described is the epiplas- 

 tral beak (Plate 10, fig. 6), and this indicates that the species is quite 

 distinct from both />. variolosa and B. sinuosa. The individual had a 

 size about that of the type of B. sinuosa; that is, the carapace was 

 probably about 700 mm. long. This beak seems to differ from that 

 of B. sinuosa in not being notched at the midline in front and in not 

 being broadly channeled along the midline on the underside. It 

 differs from that of B. variolosa in that it projects forward, at the 

 gulo-humeral sulci, from the curvature of the remainder of the lobe. 

 The lower surface of the fragment (fig. 0), which includes the whole 

 length of the symphysis between the epiplastral bones and a pari 

 of the entoplastron, is very slightly concave, becoming convex and 

 turned slightly upward in front. Fig. 7 shows a perpendicular trans- 



