PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 89 



The follo-wing communications were read : — 



1. '' The Stockdale Shales." By J. E. Marr, Esq., M.A., Sec.G.S.. 

 and Prof. H. A. Nicholson, M.D., D.Sc, F.G.S. 



2. " On the Eruptive Eocks in the Neighbourhood of Sarn, Caer- 

 narvonshire." By Alfred Harker, Esq., M.A., E.G.S. 



The following specimens were exhibited : — 



Specimens from the Woodwardian Museum, Cambridge, exhibited 

 in illustration of the papers by Messrs. Marr, Nicholson, and Harker. 



May 23, 1888. 

 W. T. Blanfoed, LL.D., E.E.S., President, in the Chair. 

 The List of Donations to the Library was read. 

 The following communications were read : — 



1. "On the Spheroid-bearing Granite of Mullaghderg, Co. 

 Donegal." By Erederick H. Hatch, Ph.D., E.G.S. (Communicated 

 with the permission of the Director-General of the Geological 

 Survey.) 



2. " On the Skeleton of a Sauropterygian from the Oxford Clay, 

 near Bedford." By B. Lydekker, Esq., B.A., E.G.S. 



[Abstract.]^ 



A description was given of a considerable portion of the skeleton 

 of a Sauropterygian from the Oxford Clay of Xempston, consisting 

 of several upper teeth, most of the mandible (of which the symphy- 

 sial region is entire), a considerable number of vertebrae mainly 

 from the " pectoral " and dorsal regions, the greater portion of the 

 two pelvic, and fragments of the pectoral limbs, and a considerable 

 proportion of the pectoral and pelvic girdles. These remains were 

 referred to Plesiosaurus philarchus, Seeley, and the various parts 

 described in detail. 



The Author discussed the advisability of retaining the forms 

 described under various generic names by Professor Seeley, under the 

 name of Plesiosaurus^ and stated his intention of employing tlie 

 latter term in its widest sense for the present. With this definition, 

 the form under consideration was shown to present characters 

 intermediate between those of Plesiosaurus and Pliosaurus, but was 

 retained provisionally in the former genus. Although a direct link 

 in the chain connecting the two genera, P. philarclius was not 

 regarded as an ancestor of Pliosaurus, since teeth undistinguishable 

 from those of the latter genus occur in the Coralline Oolite. 



* This paper has been withdrawn by the Author. 



