PLEUKOSAURID-E. 293 



Aphelosaurus lutevensis, Gervais \ 



The type and only species. About equal in size to Sapheosaurus 

 ihiollierei. 



Hob. Europe (France). 



49658. Cast of a slab of shale, showing the trunk and limbs of the 

 left side. The original is the type, and was obtained from 

 the Upper Permian of Lodeve (Herault), France. It is 

 figured by Gervais in his ' Zoologie et Paleontologie 

 Franchises/ 2nd ed. pi. lxxxiv. fig. 1. 



Presented by the Paris Museum of Natural History. 



Family PLEUROSAURID^E. 



Body greatly elongated, with not less than some fifty presacral 

 vertebrae in the type genus. Skull long and narrow, with the facial 

 portion beak-like, and the nares forming long narrow slits. The 

 skull has a distinct postorbital bar; and the digits of the pes are 

 reduced to four, the number of phalangeals in the fifth being three, 

 in place of the normal four. 



This family in addition to the type genus includes Acrosaurus and 

 Anguisaurus, Meyer ', but it does not appear certain that these are 

 really distinct. The skull of Acrosaurus closely resembles that of the 

 following specimen, although belonging to a much smaller animal. 

 Both Acrosaurus and Anguisaurus have the tail greatly elongated. 



Although there is nearly as much difference in the number of 

 presacral vertebras in the different genera of the Anguidce (Lacer- 

 tilia) as there is between Homceosaurus and Plewrosaurus, yet the 

 great difference in the cranial structure of the two latter appears to 

 be of more than merely generic value. 



Genus PLEUROSAURUS, Meyer 3 . 

 The type genus. 



Pleurosaiirus goldfussi, Meyer 4 . 



The type species. Length of skull 0,010; about 50 presacral 

 vertebras ; length of tail unknown. 

 Hob. Europe (Germany). 



1 Loc. cit. 



2 See Meyer, Fauna der Vorwelt — Kept, Lith. Schiefer, pi. xii. figs. 6-10, and 

 pi. xiv. fig. 2 ; and Palaeontographica, vol. vii. p. 231. 



3 Nova Acta Ac. Cses. Leop.-Car. vol. xy. pt. 2, p. 194 (1831). 

 * Loc. cit. 



