ORDER CROCODILIA. 



II83 



it as nearly related. Typothorax, with pitted scutes adherent to the 

 ribs, is an allied form from the reputed Trias of North America ; 

 which Professor Cope regards as foreshadowing in its dermal skeleton 

 the carapace of the Chelonia. 



Suborder 2. Parasuchia. — This extremely generalised suborder 

 is confined to the Trias, or strata of approximately equivalent age. 

 It is characterised by the absence of descending palatal plates de- 

 veloped from the roof of the mouth, so that the posterior nares (fig. 

 1083) open directly into the latter, without the intervention of a 

 secondary passage. The vomers are seen on the palate ; the middle 

 one of the three eustachian canals appears to be wanting 1 ; the 

 anterior nares are placed in the middle of the cranium ; and the 

 premaxillse have typically some twenty-one teeth, and are produced 

 into a long rostrum. A clavicle was probably present, the coracoid 

 was short and rounded like that of the Dinosauria ; while the pubis, 

 as in the latter, takes a share in the formation of the acetabulum ; 

 and each foot was probably furnished with five digits. The centra 

 of the vertebrae are amphiccelous ; and the dorsal scutes have a 

 keel-like ridge, and form only two longitudinal rows ; while those of 

 the ventral buckler (when present) are arranged in not more than 

 eight of such rows, and each scute consists of a single bone. This 

 group differs very widely from the true Crocodiles, and Dr Baur 

 now appears to regard it as a distinct order, under the name of 

 Phytosauria. 



Family Phytosaurid^e. — This family is best known by the type 

 genus Phytosaurus (Belodori) ; originally described from the Keuper, 



Fig. 1082. — Right lateral view of the skull of Phytosaurus cylindricodon ; from the Keuper of 

 Wiirtemberg. Much reduced. The vacuities in the cranium are the preorbital, the orbit, and 

 the infratemporal fossa. (After Meyer.) 



or Upper Trias of Wiirtemberg, but subsequently found in beds of 

 approximately equivalent age in both India and North America. 

 In the skull (figs. 1082, 1083) the orbit is separated by a bony bar 

 from the infratemporal fossa ; there is a large preorbital vacuity, 



1 According to Dr Koken. 



