VERTEBRATE REMAINS FROM THE DOCKUM TERRANE. 13 



dons as described by Von Me3'er.* They are subquadrate in form and 

 have a more or less obtuse longitudinal keel in the center, which does 

 not extend to the anterior or posterior borders. The latter are thinned 

 out and more or less irregular, while the lateral borders are in the larger 

 plates furnished with sutures, though of no great thickness. In the 

 larger plates irregular rugosities extend for a short distance at right angles 

 to the median keel; in the smaller plates the surface is nearly smooth. 

 There are a good many small plates without keel or sutural border and 

 which were evidently isolated in the integument of the animal. No plates 

 showing spines were discovered. 



The left frontal bone is preserved, minus a lamina from the internal 

 side of its posterior third. Its measurements are one-half greater in any 

 one direction than those of the Belodon buceros, Cope, and it differs from 

 that species and the B. Jcapjii, Meyer, in the form of its superior surface. 

 Instead of being plane as in those species, the supra-orbital border is 

 flared upward so as to divide the frontal surface into three sub-equal 

 parts, viz., a central flat-bottomed groove, and an oblique elevated 

 plane on each side of it. The surface anterioi'ly is strongly irregularly 

 pitted and ridged, much more so than the B. buceros. The posterior half 

 is smooth except at the borders. The inferior lateral ridges diverge on 

 each side to the inferior edge of the postfrontal suture. The latter ad- 

 vances to the anterior third of the orbital border as in the B. kapfii. The 

 postfrontal is smooth at the borders, but presents rugosities which gen- 

 erally run to the parietal border. The latter is rough posteriorly. 



The splenial bones unite to form part of the symphysis at an acute angle, 

 and do not diverge from the latter in the concave line displayed by the 

 B. kapfii. Their inferior surface is flattened, and is marked by three lines 

 of narrow longate fossae. The width of these bones exceeds the depth, 

 while the reverse is the case in the Episcoposaurus liorridus. 



The best preserved and most characteristic tooth is of the longate type 

 shown by Meyer to belong to the anterior part of the jaws. Of the diam- 

 eters of the base, the longitudinal a little exceeds the transverse, and the 

 two cutting angles separate a little convex interior face from a very con- 

 vex exterior face. There are a few faint traces of grooves at the base of 

 the latter. The crown is curved slightly inwards. A second well pre- 

 served crown is very diflferent. It is shorter, and stouter at the base, 

 where the transverse exceeds the anteroposterior diameter. The angular 

 lines are only visible on the apical half of the crown, and the entire sur- 

 face, except near the apex, is marked with well defined approximate 

 grooves with rounded bottoms. 



The type of tooth first described is characteristic of all Belodons, 

 but Von Meyer figures and describes a specimen of the second type 



* Pq,leontographica, Vol, VII, 1859-61. 



