Cxl PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



and others are freshwater, and as some Entomostracans even Uve 

 occasionally in one or the other medium, no certain evidence can be 

 drawn from the fossil alone as to whether the Triassic deposits were 

 those of rivers, of lakes, or of seas ; but, taking the association of fossils 

 into account, Mr. Jones seems justified in suggesting, on reference to 

 the plant-beds of Nagpur and Virginia, that " these plant-beds with 

 reptiles and crustaceans may indicate the terrestrial and lacustrine 

 conditions only of the early secoadary periods." Mr. Brodie had 

 pointed out (from footmarks) in his paper the existence of a Labyrin- 

 thodont animal, had noticed the presence of bones, teeth, and spines 

 of Acrodas, with other small teeth and scales, and recorded the ex- 

 istence of plants, and then, remarking upon the abundance of the 

 Posidono7nyay he justly says, — "^ It is singular that the Posidonia 

 should be the only shell at present known in strata of such extent 

 and thickness as the Trias [in England], and the more so, as there 

 seems no reason why the sea should not have been tenanted by other 

 contemporary forms of Mollusks equally suitable to the same con- 

 ditions of marine life :" the suggestion of Mr. Jones would remove 

 this difficulty, by favouring the idea of a large lacustrine formation. 

 In a paper by Mr. Plant, on the upper keuper of Leicester, the Es- 

 theria again performs a prominent part, being associated with plants 

 and with fish-remains ; and I may add, that Mr. Plant and Mr. 

 Jones both recognize the discernment of Mr. Morris and of Sir C. 

 Lyell, who had previously pointed out the crustacean character of 

 the Fosidonomya, though they had not fully established it by mi- 

 croscopical examination. I may observe that Geinitz places this form 

 in the Permian strata, with a remark that it strongly resembles the 

 thin shells of Cypris, and refers to the discussion by Delahaye and 

 Landriot, who maintained its crustacean character in 1848. 



Having thus given a sketch, as it were, of the labours of our Society, 

 I must for a few moments turn to those of that national institution 

 specially directed towards the development of Geological Science and 

 the advancement of its most important practical application in this 

 country : I mean the Museum of Practical Geology and the School of 

 Mining Science associated with it. Without doubt there is no institu- 

 tion in this country of the formation of which the Government may 

 well feel more proud, and there is none in which the duties allotted to 

 it are carried on with more zeal and efficiency, though quietly and un- 

 ostentatiously. Sir Roderick Murchison, its able Director-general, 

 tells us that in England maps comprising an area of 2357 square miles 

 have been published ; that others, amounting to a further area of 9.96 

 square miles, are on the point of issue, and that an area of 774 square 

 miles, comprising subdivisions of the oolitic, wealden, cretaceous and 

 tertiary groups, complicated by faults, have been geologically sur- 

 veyed preparatory to being mapped ; that in Scotland the six-inch 

 maps of Edinburgh and Haddington have received, or are receiving, 

 the geological outlines of the coal-fields, and their associated deposits ; 

 that in Ireland 1604 square miles of country have been surveyed, and 

 that sections have been run along 417 miles of wild and rugged coasts ; 

 so that we may fairly affirm that the officers employed, and especially 



