Bibliographical Notice. 69 



face tissue can be well seen. It does not appear to be correct 

 to state that no observers had described or %ured the termi- 

 nations of nerves in the Echinida before the writer of the 

 interesting little preparatory essay which T have ventured to 

 praise and criticize in a most friendly spirit. 



June 1886. 



BIBLIOGRAPHICAL NOTICE. 



Memoirs of the Geological Survey of India. Palcfontoloyia hidica, 

 being Figures and Descriptions of the Organic Remains procured 

 during the Progress of the Geological Survey of India. Pub- 

 lished by Order of His Excellency the Governor-General of India 

 in Council. Ser. x. Indian Tertiary and Post-Tertiary Vertehrata. 

 Vol. III. Part 6. SiwcdiTc andNarbada Chelonia. By 11. Lydek- 

 KEK, B.A., F.G.S., &c. With 10 plates (xviii.-xxvii.). Calcutta : 

 Geological Survey Office. London : Triibner & Co. 1885. 



In a brief introduction Mr. Lydekker dwells on the difficulty of 

 dealing with his material, a difficulty which may not be altogether 

 unconnected with the variations of form which the Cheloniau cara- 

 pace often assumes with increasing age in existing species. Many 

 of the Upper-Tertiary tortoises from the Siwaliks prove to be closely 

 allied to species which still inhabit India and adjacent countries, 

 though the terrestrial types are specifically distinct from living 

 Indian species. The remains found in the more recent Narbada 

 beds are all referred to existing Indian types. 



The descriptions open with an account of additional remains of 

 Colossochelys atlas. Among these the epiplastron is remarkable for 

 its anterior bifurcation, a character which serves to distinguish it 

 from the gigantic living tortoises. The xiphiplastron suggests, when 

 taken with the other remains, that the carapace was about 8 feet 

 long, while smaller specimens, which the author regards as probably 

 female, may have been 6 feet long. The carapace, long ago restored 

 by Falconer, shows that the pygal plates, as in the existing Man- 

 ouria emys, were not united. The shaft of the humerus agrees best 

 in proportion with the living Galapagos tortoise, Testudo elephan- 

 toj)us. The fragment indicates a bone 2 feet 4 inches long. A 

 cranium is figured and provisionally referred to this species, which 

 resembles that of Testudo ponderosa of Aldabra in its deeply concave 

 palate, which is narrower than in T. elephantina. The head is 

 estimated to have been over 9 inches long. From various resem- 

 blances the author is led to the conclusion that the Aldabra tortoises 

 are probably descendants of the old Indian stock. 



