342 Geological Society. 



Iguanian from the Ophidian vertebrae, and that, until we have the op- 

 portunity of comparing the Mosasauroid vortebroe with those of both 

 these types, the mere presence of these parts cannot be accepted as 

 conclusive. 



2. "On new Species of Procolophon from the Cap© Colony, pre- 

 served in Dr. Grierson's Museum, Thornhill, Dumfriesshire ; with 

 some Remarks on the Affinities of the Genus." By Harry Govier 

 Seeley, Esq., F.L.S., F.G.S., &c., Professor of Geography in King's 

 College, London. 



The species described by the author were named by him Proco- 

 lophon Griersoni, P. sphenieeps, and P. platyceps ; they are repre- 

 sented by skuUs imbedded in a hard red ironstone matrix, apparently 

 concretiouary, and wore collected at Donybrook, Queenstown district. 

 Cape colony. 



With regard to the systematic position and affinities of Procolo- 

 phon, the author remarked that the presence of two distinct nares 

 shown in his specimens, removed the genus from the family Mono- 

 narialia, of the order Theriodontia, in which it was placed by its 

 founder. Prof. Owen. He further discussed in considerable detail 

 the characters upon which the order Theriodontia is founded, and 

 arrived at the conclusion that this group must be regarded as syno- 

 nymous with the family Cynodontia, which, with the Dicynodontia 

 and Cryptodontia, make up Prof. Owen's order Anomodontia. The 

 genus Procolophon, displaying no distinguishable canines, does not 

 possess the chief character of a Cynodont ; and the author preferred 

 to regard it as belonging to a parent type from which the dental 

 modifications of the Anomodontia have been derived, and, from its 

 api^arent relationship to Hatteria, as forming an extinct family of 

 the Rhynchocephala. Hence the question arises, whether the 

 Anomodontia and the South -African forms described as Dinosaurs 

 might not be united with the Rhynchocephala to form a subclass of 

 Reptilia. 



3. " On the Microscopic Structure of the Stromatoporidae, and on 

 Palaeozoic Fossils mineralized with Silicates, in illustration of 

 Eozoon." By Principal Dawson, LL.D., F.R.S., F.G.S. 



The fossils included in the group Stromatoporidae occur from the 

 Upper Cambrian to the Upper Devonian inclusive, and are especially 

 abundant in the Trenton, the Niagara, and Corniferous formations. 

 The author regards Stromatopora as a calcareous, non-spicular body, 

 composed of continuous, concenti'ic, porous laminae thickened with 

 supplemental deposit, and connected by vertical pillars, most of which 

 are solid. The surface shows no true oscula ; but perforations made 

 by parasitic animals have been mistaken for such. From the struc- 

 ture, they cannot have been related either to Sponges or to Hy- 

 dractinice, and still less to Corals ; they arc truly Foraminiferal, and 



