Geological Society. 71 



vium, and a well-characterized marine post-pliocene deposit. The 

 recent alluvium is divided into inland-swamp, tide-swamp, and salt- 

 marsh. The two last occupy a shallow basin having a depth of about 

 twelve feet, the bottom and sides of which are the post-pliocene for- 

 mation. This the author divides into three groups, in the last of 

 which, constituting the elevated sand hills, no organic remains have 

 been found ; in the two former marine shells of existing species occur. 



The fossil bones of the land mammalia discovered by Mr. Cooper, 

 were found resting on the yellow sand and enveloped in the recent 

 clay alluvium. Their unworn state and the grouping together of 

 many bones of the same skeleton, render it highly probable that the 

 carcasses of the animals falling or floating into a former lake or 

 stream, sank to the sandy bottom, and were gradually covered to 

 their present depth by the sedimentary deposits from the water. 

 Among them were remains of the megatherium. Mastodon giganteum, 

 mammoth, hippopotamus and horse. The fossil shells found in the 

 post-pliocene, were species at present existing on the neighbouring 

 shores. 



The facts narrated by Mr. Cooper lead to the following conclu- 

 sions : — 1st. That the post-pliocene formation extends further south 

 than Maryland, to which it has hitherto been limited. 2nd. The co- 

 existence of the megatherium with the mammoth, mastodon, horse, 

 bison, and hippopotamus. 3rd, That the surface of the country has 

 undergone no sudden or violent change since those animals inhabited 

 it, which is proved by the absence of all traces of diluvial action in 

 the enveloping alluvium or surrounding country. 4th. That what- 

 ever changes of temperature may have taken place since that time, 

 fatal to the existence of those mammalia, the identity of the fossil 

 with the existing species of the marine shells of the coast shows that 

 the temperature of the ocean. at a period prior to the existence of 

 the megatherium, the mastodon, and the hippopotamus was such as 

 is congenial to the present marine testacea of Georgia. 



** Description of some Fossil Fruits from the Chalk-formation of 

 the South-east of England." By Gideon Algernon Mantell, LL.D., 

 F.R.S.. &c. 



The fruits described are three in number, viz. — 

 1. Zamia Sussexiensis, Mantell. — From the greensand. A cone 

 allied to the Zamia macrocephala, a greensand fossil from Kent, 

 figured in Lindley and Button's * Fossil Flora,' pi. 125, from which 

 it differs in form and in the number, size, and shape of its scales, 

 which are more numerous, smaller and more oblong than in the 

 Kentish species. It is five inches long, and at the greatest circum- 

 ference measures six inches. It was found about two years ago in 

 an accumulation of fossil coniferous wood in a sand-bank at Selmes- 

 ton, Sussex, at the junction of the Shanklin sand with the gault. 

 Dr. Mantell having sent a cast of the only specimen found to M. 

 Adolphe Brongniart, that distinguished botanist suggested that it 

 might be either the stem of a young cycadaceous plant or the fruit 

 of a Zamia, but the situation and small size of the stalk at the base 

 and the appearance of the scales, induce Dr. Mantell to refer it to 

 the latter. 



