876 Reports and Proceedings — 



is reversed, their true position being misrepresented in that author's 

 diagram, a very excusable error. 



Part II. described a sacrum, with ilia, vertebrae, a femur, etc. 

 The neural arches of the sacral vertebrae are synostosed, and so form 

 a continuous roof (simulating the vault of a cranium) of the dilata- 

 tion of the neural canal, which enclosed the sacral swelling of the 

 spinal cord. The transverse processes are long. The ilia offer a 

 general resemblance to those of Osmosaurus armatus (Owen), but 

 differ from those of this species in the relatively greater length and 

 narrowness of the preacetabular process. The similarity of con- 

 struction of this sacrum to that of Stegosaurus, described by 0. 0. 

 Marsh, and the very close resemblance of their ilia were noticed. 

 The author considered that an extremely close affinity exists between 

 these two genera, and is prepared to find that, upon the acquisition 

 of more materials, their identity may even be established. For the 

 present, he preferred to refer the Peterborough Dinosaur to Omosaurus, 

 and proposed for its specific name durohrivensis, having reference to 

 that of the old Roman settlement in that locality. 



6. " Notes on some Polyzoa from the Lias." By Edwin A. 

 Walford, Esq., F.G.S. 



The author briefly reviewed the work of Etheridge, Vine, and 

 others in the tabulating of the British Liassic Polyzoa, and mentioned 

 also the labours of Terquem and Piette, Dumortier, and others in the 

 same direction in France and Germany. He directed attention to a 

 species described by Prof. Tate from the Lias of May, Normandy, 

 under the name Spiropora liassica, and described specimens in his 

 own collection from a similar horizon in the Midlands, with which 

 it had been confounded. The English forms have very varying 

 modes of growth ; sometimes foliaceous after the fashion of the 

 Diastopora proper of Haime, at other times ramose and cylindrical, 

 like Entalophora. The latter habit, together with the long, and often 

 partly free, zooecia, suggest the relationship of the species with the 

 TubuliporcB. The exceptional state of preservation of the specimen 

 is such as to show the cells in a perfect condition, with solid circular 

 calcareous closures within the orifice of the zocecial tubes, a feature 

 common to both the foliaceous and the cylindrical forms. The 

 surface-pores are unusually well preserved, and appear to be similar 

 to those of the recent Cyclostomatous Polyzoa. The name of Tuhu- 

 lipora inconstans is proposed for the species. 



Mention was also made of other fragments of Polyzoa of doubtful 

 relationship occurring in the same beds. 



7. " On the Superficial Geology of the Southern Portion of the 

 Wealden Area." By J. Vincent Elsden, Esq., B.Sc. Communicated 

 by the President. 



The author, after referring to Sir E. Murchison's paper, published 

 more than thirty years ago, on "The Distribution of the Flint Drift 

 of the S.E. of England," proceeded to give in detail his observations 

 on the angular flint-deposits of the Arun, Adur, Ouse, and Cuckmere 

 basins, He also noticed a sandy or loamy deposit containing angular 

 fragments of ironstone, and generally a few small angular flints th at 



