Cretaceous Lizards and Rhynchocephalians. 209 



figures are not alluded to in the text. A new family, Saura- 

 nodontes, is established by Dr. Lortet for its reception, and 

 is chieflj founded on the total absence of teeth and the pro- 

 coelous vertebrae. In dealing- with the latter character the 

 author curiously contradicts himself, for in the definition of 

 the family (p. 29) the vertebral centra are stated to be con- 

 cave behind, whilst further on (p. 53) the reverse is described. 

 That the latter statement is the correct one is shown by the 

 figures on pi. iii. The skull, as in the Rhynchosauridse, has 

 no parietal foramen, and the bones described as the posterior 

 portions of the parietals appear to be the supra-temporals, 

 distinct from the squamosals. 



The position of this new family in the system is indicated 

 in the following revised scheme of the classification proposed 

 by me in 1891 (3). The Champsosauridaj, first included in 

 the Rhynchocephalia vera, are now shifted to the Protero- 

 sauria, in accordance with the recent researches of Dollo (4), 

 who has shown these reptiles to be related to Proterosaurus. 



Older RHYNCHOCEPHALIA, 

 Suborder I. PROTEROSAURIA. 



Each transverse segment of the plastron composed of numerous paired 

 pieces. Pubis and ischium plate-like. Fifth metatarsal not modified. 



A. Nasal openings distinct. 



Vertebrae conically excavated at either end, 

 with persistent notochord, all with inter- 

 vertebral hypapophyses ; limb-bones vpith- 

 out condyles ; humerus with entepicondylar 

 foramen 1. Paljeohattebiid^. 



Vertebrae fully ossified, cervicals opisthocoelous, 

 dorsals biconcave ; no hypapophyses be- 

 tween the dorsal vertebne ; limb-bones 

 with condyles ; humerus with ectepicon- 

 dylar foramen or groove 2. Pkotebosaurid^. 



B, Nasal opening single ; vertebroe fully 



ossified, feebly biconcave ; no hypapo- 

 physes between the dorsal vertebrae ; 

 humerus with ectepicoudylar groove . . 3. CHAMPSOSAuniDiE. 



Suborder II. RHYNCHOCEPHALIA VERA. 



Each transverse segment of the plastron composed of three pieces, a 

 median angulate and a pair of lateral. Pubis and ischium elongate and 

 fifth metatarsal modified, as in the Lacertilia. 



A. Jaws toothed ; vertebrae amphicoelous. 



a. Nasal openings distinct ; mandible with 

 coronoid process, the rami not united 

 by suture. Vertebrae deeply biconcave. 



