324 Reports and Proceedngs — 



in the National Museum, and although it merely relates to the 

 British Museum Collection, yet it will serve as a very good basis tor 

 a study of the extinct and other fossil Mammalia belonging to those 

 groups of which it treats. It is illustrated by thirty-three woodcuts 

 of new or little-known forms, all of which are more or less fully 

 described. 



The general systematic arrangement followed is that laid down by 

 Prof. Flower in his Catalogue of Specimens of Vertebrated Animals 

 in the Museum of the Royal College of Surgeons, part ii. (1884). 



We congratulate Mr. Lydekker upon the successful completion of 

 Part I. of his work on the Fossil Mammalia, and we look forward 

 with much interest to the continuation of his work, and trust that 

 the second part, comprising the Artiodactyle Ungulates, may appear 

 before the end of the present year. 



s,:e:po:rts j^istid iPiaociEJiBiDiisra-s. 



I. — EoTAL Society of London. 



"On Beds of Sponge-Eemains in the Lower and Upper 

 Greensand of the South of England." By George Jennings 

 HiNDE, Ph.D., F.G.S. Communicated by Henry Woodward, 

 LL.D., F.E.S. (Eeceived April 29, 1885.) 



The author said : — I have pointed out in this paper the occurrence 

 in the Lower and Upper Greensand strata of the Wealden area, the 

 Isle of Wight and the south-western counties, of beds of rock formed 

 to a large extent of the detached spicular remains of siliceous 

 sponges, and thus distinctly of organic origin. Their true characters 

 have not been generally recognized, and they have usually been 

 described as deposits of sandstone, chert, malm, hearthstone, fire- 

 stone, etc. In the Lower Greensand these beds are mainly de- 

 veloped in the lower, or Hythe, division, and they are exposed at 

 Haslemere, Midhurst, Petworth, Godalming, Tilfurston Hill, near 

 Godstone, Sevenoaks, Maidstone, and at Hythe. The sponge-beds 

 vary from three-quarters of an inch to three feet in thickness ; 

 between them, as a rule, there are intervening beds of sand or 

 sandstone. The greatest total thickness of the sponge-beds exposed 

 in one section is eleven feet. Sponge-beds are less common in the 

 higher or Folkestone division of the Lower Greensand, but they are 

 numerous at Folkestone itself, and reach a total thickness of more 

 than eight feet, and there is also a thin bed in this division at 

 Sevenoaks. The Lower Greensand strata at Faringdon, in Berk- 

 shire, is of an altogether different character to those of the same 

 formation in the area treated of in this paper, and the sponges 

 which abound therein are likewise entirely different, being calci- 

 sponges, and retaining their entire forms. 



The sponge-beds in the Upper Greensand are of two distinct 

 types, one of which is shown on the northern and western margin 

 of the Weald, and the other in the Isle of Wight, and further west- 

 ward in the counties of Wilts, Somerset, Dorset, and Devon. In 



