y\i. II. (J. Sci'lt^y oil a new Sj)€cie3 o/Plesiosaurus. 181 



baud albo tcmiinutis, et rcctricibus cxterioribus brunneis pogonio 

 externo isabellino marginato, baud albis, distingucnda. 



Hah. Xorth-east Africa {Brehm, Ileut/Iin), Palestine {Tris- 

 tram), Caucasus {Mriu'tru's), yPersIa {Dcfili'ppi), Turkestan 

 (Dode), Ca^shmere {Jerdon), North-west India {Blijth, Hume). 



XX. — On a new Species o/" Pies iosaurus yrom the Portland 

 Limestone*. By IIakuy G. Seeley, F.G.S., St. John's 

 College, Camhridge. 



When the Index to the Reptilian Remains from the Secondary- 

 strata j)reserved in the AV-oodwardian ]\[useum was written, an 

 examination of many examples of Plesiosauria had shown 

 that, with perfect specimens, good characters were available 

 by which the overgrown genus Plesiosmirus might be sepa- 

 rated into natui-al genera. Hence, when recording the few 

 remains from the Portland Oolite (p. 91), finding the charac- 

 ters of PUnsaurus blended to some extent with those of Plesio- 

 sauru.i, I did not feel it easy to volunteer an opinion on generic 

 affinities. 



Since then, Prof. Owen's memoir in the Palreontographical 

 Socictv's volume (1869) on Pliosaurus j^ortlandiciis has been 

 published ; and in the absence of associated vertebrse showing 

 the distinctive Pliosaurian characters of the neural arch and 

 centrum, I cannot but feel less confidence than Prof. Owen 

 expresses in i-egarding the paddle there figured as the type of 

 the Pliosurian hind limb. In some large-headed Plesiosaurs, 

 such as Plesiosaurus macrocephahis (Owen), the tibia and 

 fibula, and ulna and radius, become shorter than in small- 

 headed species ; and although the tarsus in Prof. Owen's 

 fossil is very similar to that of Pliosam-s from the Kimmeridge 

 Clay, the femur is more like Plesiosaurus ; and it is not im- 

 possible that the Portland specimen may typify a new genus. 

 All the limb-bones from the Portland Limestone, so far as 

 known to me, are pliosauroid, while all the vertebrai are 

 plesiosauroid. 



Therefore with some interest we received from an inde- 

 fatigable correspondent, Mr. W. R. Brodie, some vertebra; 

 which demonstrate, as conclusively as vertebrse can, the exist- 

 ence in the Portland Limestone of a new species of Plesio- 

 saurus. They were found by Mr. Brodie at the Winspit 



* Communicated bv the author, having been read before the Cambridge 

 Philosophical Society, :\ray 30, 1870. 



