369 



water thus descending through crevices being converted into va- 

 pour in subterranean hollows, and then carried off in other direc- 

 tions in the form of stufas or hot springs. I forbear to enlarge on 

 this subject at present, as a description of the facts drawn up by 

 Mr. Martin before Mr. Strickland's visit, will shortly be read to 

 the Society. 



We have received from Capt. Belcher a suite of geological spe- 

 cimens from various parts of the west coast of Africa, with remarks 

 on the reefs and sand-banks of that coast ; and a collection from the 

 Rev. W. Hennah of recent calcareous limestone and volcanic pro- 

 ducts from the island of Ascension. 



I shall next consider some papers relating more or less exclusively 

 to fossil zoology, which have been read at our meetings during the 

 last session. We are indebted to Mr. Broderip for a description of 

 some new species of fossil Crustacea and Echinodermata, which were 

 discovered by Lord Cole and Sir P. Egerton in the lias of Lyme 

 Regis. One of these crustaceans belongs to a genus intermediate 

 between the Palinurus and the Shrimp. It is of a gigantic size 

 compared to any recent species, and belongs to a division of which 

 the living types have been only met with in the arctic regions. 



Sir P. Egerton has described some peculiarities of structure in 

 the occipital bone of an Ichthyosaurus, observed in the skeleton of 

 a new and gigantic species recently discovered by Miss Anning at 

 Lyme Regis. He also states that the axis and atlas in this genus 

 are usually found adhering firmly together, and they are connected 

 by an auxiliary bone, showing that strength rather than freedom of 

 lateral motion was required in the neck of these animals. These 

 observations have been confirmed by Mr. Owen and Mr. Clift. 



It has often been a question whether the bones of birds had ever 

 occurred in strata below the chalk, some of the thin fragile bones 

 found at Stonesfield, and formerly considered to be those of birds, 

 having been ascertained to belong to Pterodactyls. In order to 

 elucidate this point, Mr. Mantell lately placed all his specimens from 

 the Wealden, supposed to be those of certain Grallas, or waders, in 

 the hands of Mr. Owen, and the result of his examination has con- 

 firmed Cuvier's opinion that they are true ornitholites. They seem, 

 therefore, to be the oldest authenticated fossils of this class hitherto 

 found in Great Britain. The rarity of such remains in geological 

 formations, especially in the marine, cannot surprise us ; for in the 

 recent shell marl of Scotland, formed in lakes much frequented by 

 water-fowl up to the moment of their drainage, no bones of birds 

 have as yet been detected amongst the numerous relics of deer, ox, 

 pig, and other quadrupeds occurring in the marl. 



Mr. Darwin, in his travels in South America before alluded to, 

 found, in crossing the continent from the Rio Negro to Buenos 

 Ayres, many large bones of Mastodons, and other remains of the 

 Mastodon at Port St. Julian, 50° S. lat., at a distance of more 

 than six hundred miles from the former. He also saw, in the 

 gravel of Patagonia, many bones of the Megatherium, and among 



VOL. II. g A 



