NO. 2292. 



NEW FOSSIL TURTLES— GILMORE. 



121 



Compared with B. pulchra the carapace has a more pointed anterior 

 end and a less sinuous margin. It is estimated that the shell had a 

 greatest length of about 280 millimeters with a greatest width of 244 

 millimeters. It is moderately arched transversely. The surface of 

 the carapace is slightly sculptured by a combination of nodes and 

 ridges. A low rounded inconspicuous, interrupted, longitudinal 

 ridge extends along the median line of the neural bones. On several 

 of the neurals there are on either side numerous oblique ridges and 

 grooves all faintly mdicated. Several node-like elevations occur 

 here and there along the front peripheral margin, and less weU-defined 

 ones are scattered over the surfaces of the costal bones. The plastron 

 is smooth. 



The nuchal has a greatest width of 44 millimeters, which is reduced 

 to 31 millimeters on the margin; the length is 20 millimeters. It is 

 broadly excavated behind for the reception of the broad convex end 

 of the preneural. Neurals 1 to 5 are present in this specimen, and all 

 are wide in front, but with much narrowed posterior ends. The 

 first, as compared Math B. pulchra, is greatly elongated. Their 

 principal dimensions are given in the table: 



Measurement of neurals in millimeters. 



The fifth costal narrows to its distal end as in B. pitlchra. The 

 peripheral bones present are mostly quadrangular in shape, except 

 the first, which is triangular and very small. The second and third 

 are about as long as high, but the succeeding ones, including the 

 eighth, are longer than their height. 



The nuchal scute is smaller than in B. pulckra, measuring 20 

 milhmeters wide and 7 millimeters fore and aft. 



The first vertebral scute is as broad as long, whereas in B. pulchar 

 it is nearly twice as broad as long. This scute is also characteristic 

 in being greatly narrowed toward the front. Posteriorly it has a 

 greatest width of 49 millimeters, which reduces to 19 millimeters at 

 the anterior end. 



Measurements of vertebrals, in millimeters. 



