526 * E. C. CASE 



The character of the skull is shown in Figures i, 2, and 3. 

 It is astonishingly small for the size indicated by the vertebral 

 column. The basi-cranial region is distinctly phytosaurian in size 

 and the arrangement of the elements but the skull as a whole 

 shows several marked peculiarities. There is a single large lateral 

 temporal fenestra with no trace of an incipient or disappearing 

 upper fenestra. The quadrate is so far reduced that it occupies 

 a depression bounded by the opisthotic and the quadrato-jugal ( ?) ; 

 the large, laterally directed orbits are preceded by large, elongate 

 antorbital vacuities and these by smaller, elongate narial openings 

 which lie entirely on the side of the nose; the teeth are small (as 

 indicated by the sockets and a single 

 poorly preserved tooth), are of equal 

 size throughout the length of the 

 maxillary, and were set in deep 

 sockets; the posterior surface of the 

 skull is completely closed except for 

 the large foramen magnum and two 

 small openings, amounting only to 

 foramina, which occupy the position 



of the posterior temporal openings. Fig. 3.— Posterior view of the skull 



The anterior end of the skull is oi Desmatosuchus spwensis, xi 

 missing but there is every indication 



that the nose was short. The close anchylosis of the bones and 

 the coarse sculpture of the upper surface of the skull prevents the 

 determination of many of the sutures; such as have been located 

 are indicated upon the figures. As it has been shown by v. Huene 

 and others that Aetosaurus possessed upper temporal openings 

 and as such openings are present in the Proterosuchia, their absence 

 in the form here described is alone sufficient to indicate its isolated 

 position. 



The vertebral column so closely approaches that of the Para- 

 suchia that it need not be discussed in a preliminary description. 



The dorsal armor consists of four rows of plates, two on each 

 side of the median line. The rows are made up of incomplete 

 rings covering the dorsal portion of the body. Whether there 

 was any armor on the sides or the abdomen is uncertain; a single 



