Geological Society of London. 379 



the chevron bones free from the artic'nlar margins, forming large 

 prominent unequal tubercles on the base of the centrum. The cora- 

 coids are as broad as long, nearly square, not prolonged in front of 

 the humeral articulation. The scapula are sickle-shaped, thin 

 towards the median line, and without way suprahumeral process. 

 The pubic bones are transversely oblong, and the ischial bones more 

 than usually triangular, owing to there being no forward prolonga- 

 tion to meet the pubes. The iliac bones are less expanded at the 

 proximal end, and relatively longer than usual. In the limbs the 

 ulna and radius approximate in form to those bones in Pliosaurus, 

 and the phalanges resemble those of Pliosaurus in not being com- 

 pressed from side to side. There are six polygonal carpal bones. 



Discussion. — Mr. Hulke said that it was only with great diffidence that he 

 ventured to speak on the anatomy of Plesiosaurs. He urged that a suspension of 

 judgment was desirable, as many points in the anatomy of these Saurians are but 

 imperfectly known, seeing that bones which are displayed in one specimen may be 

 concealed in the matrix in another. He thought that two types might be recog- 

 nized among Plesiosaurs, — one with the coracoids extended longitudinally, the 

 other with those bones transverse. 



Mr. Charlesworth regretted that the Palaeontologists who had specially written 

 on the subjects treated of by Mr. Seeley were not present, and thought that the 

 author was rather too dogmatic in his tone. He suggested that the distribution of 

 casts of typical specimens to different museums would be of great advantage. 



Mr. Seeley stated that he had endeavoured privately to bring his own views into 

 harmony with those of other writers ; and having enjoyed some facilities for arriv- 

 ing at the precise meaning of Prof. Owen's determinations, he wished to express 

 his sense of that gentleman's generous appreciation of modern scientific progress 

 and discovery. He believed that the apparent difference of his own determinations 

 from those of previous writers was due rather to indecision of determination and 

 absence of evidence for the purpose of determination in former times than to any 

 fundamental differences between himself and others. 



S. " On the Eemains of Lahyrintliodonta from the Keuper Sand- 

 stone of Warwick, preserved in the Warwick Museum." By L. C. 

 Miall, Esq. Communicated by Prof. Huxley, F.R.S., F.G.S. 



In this paper the author first noticed the remains of Labyrin- 

 thodonts from the Warwickshire Keuper, acquired by the Warwick 

 Museum since 1842, the date of Prof. Owen's memoir on this subject, 

 and then reviewed the determinations of Prof. Owen. He considered 

 that Labyrintliodon ventricosus, Owen, is not a distinct species, and 

 that L. scutulatus, Owen, has not been proved to be a Labyrinthodont. 

 The species as identified by the author are as follows : — 



Mastodonsaurus Jcegeri, von Meyer. 



pachygnathus, Owen. 



Ldbyrinthodon leptognathus, Owen. 



Diadetognatlius (g. n.) varvicensis, sp. n. 

 In conclusion the author described some of the structural pecu- 

 liarities of the teeth of various Labyrinthodonts. 



III.— May 27th, 1874.— John Evans, Esq., E.R.S., President, in 

 the Chair. The following communications were read : — 



1. " On the last Stage of the Glacial Period in North Britain." 

 By T. F. Jamieson, Esq., F.G.S. 



