56 PROCEEDINGS OF THE NATIONAL MUSEUM vol.91 



In view of these facts the material described is referred to a new 

 species of the genus Dinosuchus Gervuis {non Holland) , which may 

 be called Dinosuchus neivensis, named for the city of Neiva near 

 which it was found. 



Genus DINOSUCHUS Gervais, 1876 



Generic charactei's — As Gervais never separated the generic char- 

 acters from those of the species D. terror^ the following designation 

 may be given: Size gigantic, vertebrae procoelian and massively 

 constructed. 



Relationships. — The genera Dinosuchus Gervais, Purusaurus 

 Kodriguez, anc? Brachygnathosuchus Mook have been treated quite 

 differently by recent authors. Nopcsa, in 1924, considered 

 Brachygnathosuchus to be a synonym of Pwrnsaurus, and Dinosuchu^s 

 to be independent. Because of the latter interpretation he proposed 

 the name Phohosuchus for Holland's Deinosuchus. Mook, in 1934, 

 considered Purusaurus to be a synonym of Dinosuchus^ and 

 Brachygnathosuchus to be independent. Patterson, in 1936, consid- 

 ered Brachygnathosuchus to be a synonym of Dinosuchus, and 

 Purusaurus to be a synonym of Caiman of Spix. 



At the present time it appears most consistent with the incom- 

 pletely known characters of these forms and with their geologic 

 levels to consider the Cretaceous Dinosuchus to be valid and inde- 

 pendent, and to consider the upper Miocene or lower Pliocene 

 Purusaurus and Brachygnathosuchus to be valid and to be closely 

 related to Caiman. 



DINOSUCHUS NEIVENSIS, new species 



Plates 4-9 



Specific characters. — External mandibular foramen unusually large 

 in proportion to the size of the jaw elements surrounding it, jaw 

 relatively long and slender, posterior teeth relatively small and close 

 together. 



Description of ^naterial. — Five maxillary alveoli are visible on this 

 specimen. The first is large and is slightly longer than it is broad. 

 The second is larger than the first. Its external border is incomplete ; 

 consequently its proportions are difficult to determine. The last 

 three alveoli are approximately equal to the first in size; they appear 

 to be subcircular, although their borders are not entirely visible. 

 Badly mutilated stumps of teeth are visible in these alveoli. 



The anterior and posterior ends of the lower jaw section that is 

 attached to the portion of the maxillary noted above exhibit sections 

 of alveoli 12 cm. deep and fragments of teeth of corresponding size. 

 Another section of the right ramus was located much farther back 

 than the one noted above. The anterior end of the right external 



