Oeohgical Society. 153 



compared the structure of this stem with that of other Sigillarians, 

 and remarked that it seemed to come within the limits of the genus 

 Sigillaria, but to belong to a low type of that genus, approaching 

 Lepidodendron in structure — those of the type of 8. elegans, Br., and 

 S. spintdosa, Renault, being higher in organization, and leading 

 towards the still more elevated type described by him in 1870. He 

 further discussed the supposed alliance of these trees with Gymno- 

 sperms, and the probability of the fruits known as Trigonocarpa 

 being those of Sigillaria, and expressed the opinion that the known 

 facts tend to show that there may be included in the genus tSigil- 

 laria, as originally founded, species widely differing in organization, 

 and of both Gymnospermous and Acrogenous rank. 



March 7, 1877.— Prof. P. Martin Duncan, M.B., F.E.S., President, 

 in the Chair. 



" On the Vertebral Column and Pelvic Bones of Pliosaurus 

 Evansi (Seeley), from the Oxford Clay of St. JS'eot's, in the ^^'ood- 

 wardian Museum of the University of Cambridge." By Harry Go- 

 vier Seeley, Esq., P.L.S., F.G.S., Professor of Geography in King's 

 College, London. 



In this paper the author described some bones obtained by J. J. 

 Evans, Esq., in the lower part of the Oxford Clay at Eynsbury, 

 near St. Neot's. They consisted of thirty-seven vertebrae, twenty- 

 one of which are cervical, and apparently complete that series. 

 These presented the characters of the cervical vertebrae of the typical 

 Pliosaurs of the Kimmeridge Clay. The i-emains of the pelvis included 

 a pubic bone showing a close correspondence in form with those of 

 the Pliosaurs of the Kimmeridge Clay of Ely, and an ischium. 



2. " Supplementary Notes on the Fauna of the Cambridge Green- 

 saud." By A. J. Jukes-Browne, Esq., B.A., F.G.S. 



This paper was supplementary to one communicated to the Society 

 by the author in 1875, in which he maintained that the Upper 

 Greensand does not extend further in a north-westerly direction 

 than "West-End hill, near Cheddington, in Buckinghamshire, that 

 the Cambridge Greensand is merely a nodule-bed at the base of the 

 Chalk Marl, resting uuconformably upon denuded Gault, to the 

 upper part of which the greater portion of the fauna belongs, and 

 that the remainder of the Fauna, belonging to the deposit itself, con- 

 sists of species proper to the Chalk Marl rather than to the Upper 

 Greensand. The object of the paper was to indicate ceitain addi- 

 tions to, and corrections in, the list of fossils upon which these 

 conclusions were supported. The following Gault species were indi- 

 cated as not previously identified in the Cambridge Greensand : — ■ 

 Nautilus arcuutus, Desh. ; N. i)icequalis. Sow. ; TurrUites elegans, 

 D'Orb. J? T. Emericianus, D'Orb. ; Ornithopus histocheila, Gardn ; 



