302 SAUROPTEKYGIA. 



together with that of the ventral aspect of the left pes ; 

 from Kimberley. A plaster cast in relief has been taken of 

 the caudal vertebrae. Although rather smaller this speci- 

 men closely resembles the corresponding regions of the 

 skeleton of the American form figured by Cope. The 

 five rows in the distal row of the tarsus are distinctly 

 shown ; and the fifth digit, which is incomplete in Cope's 

 specimen, is entire. The numbers of the phalangeals in 

 the five digits are 2, 3, 4, 5, 4 ; the fifth digit being the 

 longest. Presented by Captain J. /Scott Helps, 1878. 



49974 b, Slab of shale showing an impression of part of the caudal 

 region and of the distal extremity of the right pes of the 

 same individual. Presented by Capt. J. Scott Helps, 1878. 



Mesosaurus tumidus (Cope 1 ). 



Syn. Stereosternum tumidum, Cope 2 . 



So far as can be seen at present there appear to be no characters 

 by which this form can be specifically distinguished from the type 

 species ; but since it has received a distinct name and is from a widely 

 distant locality it is provisionally allowed to stand as a species. 



Hab. South America. 



R. 536. Slab showing the ventral surface of the dorsal and part of 

 the caudal region, together with the impression of the 

 dorsal aspect of the imperfect limbs and the anterior 

 part of the caudal region ; from beds which are probably 

 of Lower Mesozoic age at San Paolo, Brazil. A plaster 

 cast has been taken from this specimen, which shows the 

 limbs in relief. This specimen agrees precisely with the 

 type skeleton figured by Cope in the ' Proc. Amer. Phil. 

 Soc/ vol. xxiii. pi. i. The distal row of the tarsus is not 

 clearly shown • the humerus, allowing for the circumstance 

 that the dorsal aspect is seen in the one and the ventral in 

 the other specimen, is absolutely indistinguishable from 

 that of the type skeleton of M. tenuidens, the entepicondylar 

 foramen being clearly shown. A skeleton from the same 

 deposits is described by Cope in the ' Amer. Nat.' vol. xxi. 

 p. 1109, which shows the skull. The foramen on the 

 humerus is described as being ectepicondvlar, which 



1 Proc. Amer. Phil. Soc. vol. xxiii. p. 7 (1886). — Stereosternum. 2 Loc. cit* 



