48 



BOTTOSAURUS PEKBXTGOSUS, Cope. 



Bottosaurus perrugosus, Cope. 1875. Report U.S. Geol. Survey Terrs., vol. ii. Vertebrata of Cretan 

 ceous Formations of the West, p. 68, pi. vi, figs. 5-8. 



A left maudibular ramus, from which the posterior ends of the dentary and splenial 

 bones and the articular and coronoid elements are missing. 



The supra-angular shows, on its inner posterior surface, the facet for the articular 

 bone, and also in its lower border the posterior end of the external mandibular foramen. 

 The lower margin of the internal mandibular foramen is seen in the anterior half of the 

 angular. The external surface of the dentary shows small, deep pits directed forward 

 and inward, from each of which a shallow groove passes backward for a short distance ; 

 the pits are arranged in somewhat obscure longitudinal rows. The lower outer surface 

 of the angular is rugose, from the presence of deep grooves running in a longitudinal 

 direction. This outer sculpture changes, in the supra-angular, into an irregular and bold 

 network of ridges enclosing deep, sunken arese. Altogether the surface markings are as 

 shown by Cope in his figures. 



There are sixteen sockets for teeth, the second, third and fourth of which, counting 

 from the front, still retain a hollow root. The symphysis is well shown. The front end 

 of the splenial enters into the formation of nearly one-fourth of the symphysis. A for- 

 amen passes through the splenial immediately behind the symphyseal surface. 



The species is still further represented, in the collections, by the occiput of another 

 individual, obtained in 1901, and requiring further study. Numerous vertebrae and bony 

 scutes of Crocodilia have also been obtained, some of which will probably be found to 

 belong to this species 



Measurements. 



M. 



Estimated length of ramus • 355 



Width in front -031 



Height in line with posterior oiargin of external mandibular foramen -053 



Width of lower border where the last measurement was taken -016 



Height of symphysis -018 



Length of same .... approx ■ . . . • 047 



Width of first two sockets -Oil 



Length of next three ■ 0055 



Length of tenth and eleventh sockets ■ 008 



Length of fifteenth socket ■ • ■ • 006 



Distance between outer edges of quadrates, posteriorly ■ 201 



Height of foramen magnum -014 



Belly Eiver series, Eed Deer river, 189*7, 1898 and 1901. 



