12 Frederick Chapman: 



•column is well-marked by a deep, interrupted groove. The sutures 

 of the costal plates are faintly visible. The impressions of the 

 bones of the pelvic girdle are also seen. On the ventral side 

 impressions of the bones of the plastron may be made out, and also 

 ithose of the epidermal plates; of the latter the most strongly 

 marked are the grooves between the pectoral and abdominal 

 shiieldsi. 



This fossil cast is referable to the genus Emydura, Bonaparte,^ 

 to which the Murray Mud-tortoise belongs. From all appearances 

 the fossil may be referred, with some reservation, to the same 

 species, Emydura macquariae, Gray sp.2 



The length of the fossil specimen when complete was about 28 

 .cm., as against 27 cm. of a full-grown living specimen. ^ Breadth, 

 about 15 cm. A living example from Wahgunyah, mentioned by 

 McCoy, shows almost identical proportions. This fossil is slightly 

 broaden in proportion, both across the carapace and plastron, than 

 the living specimens, but this difference seems to be due to com- 

 pression. 



Observations. — The Murray Mud-tortoise is common in the 

 Biver Murray and its tributaries and branches, but is not found in 

 Victoria in rivers flowing to the south. This curious point in its 

 local distribution may indicate the once northern trend of the 

 rivers in the Casterton district, which now join the Glenelg. 



Anent the discovery of the specimen, the question arises whether 

 this ironstone deposit bears any relationship to that occurring at 

 Redruth, which yielded Eucalyptus and Banhsia leaves, and a 

 bird's feather. 4 Carapook is in the same district as Redruth, and 



1. Arch. f. Naturgeschichte, 1838, Vol. I., p. 140. 

 .2. Hydraspis macquarii. Gray, 1831, Syd. Rept., p. 40. 



Platemys viacquariae , Gray sp., Dumeril and Bibron, Erp. Gen., Vol. II., 



p. 438. 

 Hydraspis victoriae. Gray 1842, Zool. Misc., p. 55. 

 Chelymys mncquaria (pars), Gray, 1844, Cat. Tort, p. 42 . 

 Euchelyinys sulcifera. Gray, 1871. Ann. Mag. Nat. Hist. ser. 4, Vol. 



VIII., p. 118. 

 Euchelymys sulcifera. Gray, 1872, Proc. Zool. Soc. Lond., p. 508. 

 Chelymys victoriae (pars), Gray, Proc. Zool. Soc. Lond., p. 506, pi. 



XXVII. 

 Chelymys macquaria, Cuvier sp. McCoy,, 1884, Prod. Zool. Vict. pp. 11-14, 



pi LXXXII. and LXXXIII. 

 Emydura macquariae. Gray sp. Boulenger, 1889, Cat. Chelonians, 

 Rhynchocephalians and Crocodiles in the Brit. Mus., p. 230, 

 Fig. 63. 

 Emydura macquariae, Lydekker, 1889, Cat. Foss, Rept. and Amphibia, 

 Brit. MuB., p. 169. 

 :3. Prod. Zool. Vict., Vol. I., 1884, p. 12. 



-4. See Proc. Roy. Soc. Vict., Vol. XXIII. (N.S.). pt. I.. 1910. pp. 23-26, pis. 

 IV., V. 



