370 Revieus — Indian Pretertianj Vertehrata. 



V. — Memoiks of the Geological Survey op India. 

 Pal^ontologia Indica. 



1. Indian Pretektiary Vertebrata, Series IV. Vol. I. Part IV. 

 The Labyrinthodont from the Bijori Group. By K. Lydkk- 

 KER, B.A., F.G.S., F.Z.S. Eoyal 4to. pp. 16, with 4 Plates. 1885. 



AS far back as 1865, Prof. T. H. Huxley described the remains 

 of Dicijnodon orientalis, HiixL, and of Gonioglyptus longiiostrts, 

 Huxl., from the Panchet group, Damuda series, Gondwana System of 

 India.' These basal rocks of the secondary section, which may be 

 considered homotaxial with the Triassic or Permian rocks of Europe, 

 have also by their fossil remains an affinity with the Keptiliferous 

 Triassic deposits beds of South Africa.^ 



Mr. R, Lydekker in the present memoir makes us acquainted with 

 a new and very interesting form of Labyrinthodont reptile from 

 Bijori, in the Central Provinces, for which he has proposed the 

 genus Gondwanosaurus, with the trivial name of Bljoriensis. The 

 specimen comprises the skull and a considerable portion of the axial 

 skeleton; most of the bones have disappeared and are represented 

 by moulds or cavities in the sandstone matrix. The skull agrees 

 very closely in general size with that of Loxomma Allmanni, Huxl., 

 from the Coal-measures of Northumberland (see Ann. and Mag. 

 Nat. Hist. ser. 4, vol. xiv. pi. iv.), and it may be assumed that the 

 present specimen indicates an animal of about the dimensions of that 

 species. The structure of the teeth, the presence of epiotic bones, 

 of a parietal foramen, and the structure of the thoracic shield, leave 

 no doubt of the labyrinthodont nature of the specimen. 



" Gondwanosaurus is evidently a more specialized type than 

 Archegosaurus, although, if the occipital condyles were really absent, 

 it agrees with the family Arcliegosauridce, and differs from the 

 Actinodontidce. The specialization indicates an approach to the 

 higher labyrinthodonts like Mastodonsaurus, and Labijrinthodon; 

 this being marked by the presence of large tusks in both jaws 

 within the outer series (a character which is common to several of 

 the American Actinodontidm) , and of the inner articular buttress to 

 the mandible. The absence of a post-articular process to the 

 mandible is a character in which it approaches Loxomma ; and it is 

 thus easy to see how the higher forms have been derived from the 

 primitive Arcliegosauria. If Bhytidosteus belong to the section, it 

 indicates still more completely the transition, since the structure of 

 the teeth is almost precisely intermediate between that of Actinodon 

 and Archegosaurus on the one hand, and Mastodonsaurus on the 

 other. The anchylosis of the mandibular symphysis (which, it may 

 be remarked, is a very characteristic feature of the Crocodilia) in 

 Gondwanosaurus is unknown among all the large European labyrin- 

 thodonts of which the mandible is figured, although it occurs in 

 Bhytidosteus ; it is not mentioned whether it is found in any of the 



1 See Palseontologia Indica, series iv. vol. i. pt. 1, 1865, pp. 24. 



2 See papers by Dr. Ottokar Feistmantel on the Goudwina Series of India, Geol. 

 Mag. 1876, Decade II. Vol. III. pp. 481-491, and Vol. IV. 1877, pp. 188-189. 



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