u66 



CLASS REPTILIA. 



any other Dinosaurs, although it has a distinct inner trochanter. 

 In all cases the dorsal vertebrae are amphiccelous. 



Family Anchisaurid^e.- — -The least specialised forms constitut- 

 ing this family, of which the name must be considered provisional, 

 are mainly known from beds of Triassic age, and 

 are typically represented by the North American 

 genus Anchisaurus (Amphisaurus). The cervical 

 vertebrae are amphiccelous ; the pubes are slender 

 rod-like bones ; and there are five digits in both 

 the manus and the pes. The teeth (fig. 1066) 

 usually have comparatively thick and short crowns, 

 with a slightly convex posterior border, and 

 more or less oblique serrations, which occupy the 

 whole of both borders. Thecodontosaurus occurs 



in the Lower Keuper near Bristol ; the teeth of 



Fig. 1066. — Outer 

 aspect of the crown 

 of a tooth of Theco- 

 dontosaurus filatyo- 

 don ; from the Lower 

 Keuper near Bristol. 



the type species being much smaller than the one 

 figured in the woodcut. Anchisaurus (which, according to Profes- 

 sor Marsh, is identical with a form described at an earlier date un- 

 der the preoccupied name Megadactylus) occurs in the reputed Trias 



of the United States • but no evidence 

 has yet been presented to show how 

 it differs from the European genus. 

 The writer last quoted includes in this 

 family the American Triassic genera 

 Bathygnathus and C/epsysaurus, both 

 of which are still very imperfectly 

 known. Here may be mentioned the 

 genus Massospondy/us, from the Karoo 

 system of South Africa and the Maleri 

 stage of the Gondwana system of India, 

 of which a tooth is shown in fig. 976 

 (p. 1049), and the centrum of a dorsal 

 vertebra in fig. 1067. These vertebrae 

 approximate to those of Megalosaurus, 

 and have a fusiform internal cavity. 



Finally, it is highly probable that 

 an amphiccelous cervical vertebra ob- 

 tained from beds of unknown Meso- 

 zoic age in Bathurst Island, Arctic 

 America, and described under the 

 name of 

 Dinosaur 



to the present or following family. This vertebra agrees approxi- 

 mately in size with that of Calamospondylus (fig. 107 1), but has free 

 cervical ribs and a neural spine ; the length and curvature of the 



Fig. 1067. — Lateral and inferior as- 

 pects of the centrum of a dorsal verte- 

 bra of Massospondylus carinatus ; from 

 the Karoo system of Basutoland. One- 

 half natural size. 



Arctosaurus, indicates a 

 less closely allied 



more or 



