r 60 ] 



the Atlantic, the Pacific, and elsewhere, the component parts of 

 ■which were similar to our chalk cliffs, mountain limestone, or coal 

 formations. The first two were made iip of minute organisms, and, 

 takincf into consideration the time necessary to form these rocks, 

 the age of the earth must be pushed much fui-ther back than where 

 it had been placed by many geologists. 



The aqueous rocks bore distinct evidences of having been 

 formed under water ; and in the igneous rocks, more particularly 

 in granites, minerals were found ; while many rocks supposed to 

 be igneous contained water, glass, stone, and gas cavities. 



One stumbling block to independent Mici'oscopiciil research 

 amongst rocks was that so much aid was required from the 

 lapidary's wheel, and the preparing of specimens for microscopic 

 inspection thus became an expensive amusement. 



The meeting then became a conversazione, when about six 

 dozen sections, supplied by Mr. Wonf or, were exhibited, by different 

 gentlemen present amongst the principal being granite, porphyry, 

 felspar, jasper, obsidian, basalt, pitchstone, quartz, agate, lime- 

 stone, oolites, chalk, coal, and lignite. 



February 14th. 



ORDINARY MEETING.— MR. T. DAVIDSON, F.R.S., 

 F.G.S., ON "WHAT IS A BRACHIOPOD?" 



Having been requested by some members of the Brighton 

 Natural History Society to tell them what a Brachiopod is, he would 

 endeavour to do so in as brief a manner as so extensive a subject 

 would admit. All were aware'that it was very often much easier to 

 put a question than to obtain an entirely satisfactory answer, and 

 he was consequently sorry to have to begin his few observations on 

 a very extensive group of organisms by stating that zoologists and 

 comparative anatomists had not yet entii-ely agi-eed as to the exact 

 position it should occupy among the invertebrate animals. The 

 first species belonging to the class were imperfectly and quaintly 

 described and figured by Prince Pabio Oolumna, as far back as 

 1606, and for many years were supposed to be referable to the genus 



