318 Geological Society. 



teeth both in the palate and the mandible. He next described a new 

 species, under the name of Endothiodon uniseries, founded upon the 

 fore half of a skull, having only a single row of teeth in the palate, 

 a character which may prove to be of generic importance. The 

 author finally discussed the relationships of this genus, which he re- 

 regarded as belonging to the order Anomodontia, and as showing, 

 like Oudenodon, traces of derivation from Dicynodon in the presence 

 of caniniform processes in the upper jaw. The development of 

 teeth interior to the alveolar margins in both jaws was to be re- 

 garded as a character of family value ; and the author remarked 

 upon the interest of the continuance of a common Ichthyic and 

 Batrachial dental character in exceptional cases among the Reptilia 

 up to the establishment of the Crocodilian type, above which, in the 

 vertebrate series, calcified palatal teeth no longer appear. 



2. " Note (3rd) on Eucamerohis, Hulke, Ornithopsis, Seeley, = 

 Bothriospondiilus magnus, Owen, = Chondrosteosauriis magnus, 

 Owen." By J. W. Hulke, Esq., E.R.S., F.G.S. 



In this paper the author gave a description of an unusually 

 perfect dorsal vertebral centrum of Ornithopsis, and some additional 

 information respecting the cervical and anterior dorsal vertebra?. 

 He further compared the prsesacral vertebras with those of several 

 recently discovered Dinosaurians of the Colorado region, showing 

 several agreements, but also such differences as to prove the 

 generic distinctness of Ornithopsis. He discussed the question of 

 the nomenclature of the species indicated in the title of his paper, 

 and maintained that the name Ornithopsis ought to be adopted for 

 the single genus to which he referred them. 



3. " Description of the Species of the Ostracodous Genus Bairdia, 

 M'Coy, from the Carboniferous Strata of Great Britain." By Prof. 

 T. Rupert Jones, F.R.S., F.G.S., and James W. Kirkby, Esq. 



The long persistence of the genus Bairdia, from the Silurian 

 period to the present day, and its essentially marine character, 

 were first noticed ; also the relatively rare occurrence of any species 

 of Leperditia, Beyrichia, and KirTcbya (associates of Bairdia in 

 Carboniferous strata) in freshwater or estuarine beds. Carbonia, on 

 the other hand, was confined to the fresh or brackish waters in 

 which the Coal-measures were formed. The difficulty of defining 

 the species of Bairdia from carapace-valves alone, without limbs 

 and soft parts, and the possibility of several genera being grouped 

 under this head, were mentioned. The species of Bairdia described 

 and figured in this paper were, it is believed, all that have been 

 found in the British Carboniferous rocks, with the exception of 

 M'Coy's B. gracilis. Two of Count Miinster's Bavarian Bairdiiv, 

 from Hof, have not yet occurred with us ; neither have four of 

 Dr. D'Eichwald's Russian Carboniferous species, nor the Australian 



