Geological Society of London. 329 



Silurian seas of forms of Bryozoa which, though very alDundant in 

 the Oolites and all subsequent periods, were not generally supposed 

 to have existed in the Palceozoic period. 



4. "On a New Species of Flesiosaurus {P. Conybeari) from the 

 Lower Lias of Charmouth, with Observations on F. megacepliahis, 

 Stutchbury and F. hracliyceplalus, Owen." By Prof. W. J. Sollas, 

 M.A., F.E.S.E., F.O.S., etc.. Professor of Oeology in University 

 College, Bristol ; accompanied by a Supplement on the Geologieal 

 Distribution of the Genus Pkslosaurus, by G. F. Whidborne, Esq., 

 M.A., F.G.S. 



The greater part of this paper was devoted to the description of a 

 remarkably fine specimen of Plesiosaurus from the Ammonites-obtusus 

 zone of the Lower Lias, Charmouth. Its distinctive characters are 

 as follows : — 



1. The length of the skull is 19-7o in., taken from the anterior 

 extremity of the lower jaw to the posterior margin of the quadrate. 



2. There are sixty-six vertebras, of which thirty-eight are cervical, 

 twenty-one dorsal, two sacral, and five caudal. 



3. The length of the neck is 83 in., and the cervico-cephalic 

 index 2-i*l in. 



4. The length of the cervico-dorsal series is 136 inches, and the 

 cervico-dorsal-cephalic index is 14-6. 



o. The length of the centrum in the anterior cervical vertebras is 

 equal to the height, and greater than the breadth of the articular 

 face. In vertebra xv. the measurements are — length 2 in., breadth 

 l*o inch, height 2 inches. 



6. In the posterior cervical vertebrae the breadth of the articular 

 face is greater than the length or height, but the latter two dimen- 

 sions remain equal. 



7. The neural spines increase in size up to vertebra xl., in which 

 they measure 4*75 inches in length. 



8. The neural spines ai'e inclined backwards as far as vertebra Iv. ; 

 past this, up to Ivii., they are inclined forwards ; but afterwards they 

 again incline backwards. 



9. The humerus and femur are nearly equal in length, the femur 

 being slightly the shorter. 



For the species the name of P. Conybeari is proposed. P. Cony- 

 beari agrees closely with P. Etheridgii in the relative length of head 

 and neck ; but it has eight more cervical vertebras than the last- 

 mentioned species. In the number of the cervical vertebras it agrees 

 with P. liomalospondylus, but has a much larger cervico-cephalic 

 index. 



5. " On certain Quartzite and Sandstone Fossiliferous Pebbles in 

 the Drift in Warwickshire, and their probable identity with the true 

 Lower Silurian Pebbles, with similar fossils, in the Trias at Budleigh 

 Salterton, Devonshire." By the Rev. P. B. Brodie, M.x\., F.G.S. 



The author notices some previous remarks upon these pebbles, 

 which, in Warwickshire and elsewhere, either occur in the Trias or 

 have been derived from it. To account for these, he supposed that 

 there had been a more northerly extension of Silurian rocks than 



