151 



zone. Beneath these are beds of white and pink-coloured marl- 

 stone and marl, inclined at 25° to 30°, and distinguished by Potamides 

 Lamarckii, and a new species of Cyclas, named C.Aqua? Sextiae, and 

 these pass downwards into a red-sandstone (Molasse) and a coarse 

 conglomerate (Nagelfleu), the town of Aix being situated at the base 

 of the whole of the above series. 



In continuing the sectional line to the S.W., all the district be- 

 tween Aix and Fuveau is made up of parallel ridges of fresh-water 

 rocks ; the most northerly con tabling red marl and fibrous gypsum, with 

 Limnseae and Planorbes (P. rotundatus): the intermediate range is 

 of mere earthy limestone, containing Limnsese and Gyrogonites, with 

 micaceous sandstone and shale ; and lastly, the coal-field of Fuveau 

 is described as composed of gray, blue, and black compact lime- 

 stone and shale, with stony bituminous coal of good quality j the 

 united thickness of the different seams of which amounts to about 

 5 feet. The fossils characterizing the carboniferous strata are 2 new 

 species of Cyclas, named C. cuneata and C. concinna, a Melania, 

 named M. scalaris ; Planorbis cornu, and a large species of Unio. 

 Casts of Gyrogonites were observed even in the coal itself, and the 

 charcoal seemed in some instances to be made up of a plant resem- 

 bling Endogenites bacillare of Brongniart. 



The authors remark that these lower members of this great tertiary 

 deposit differ in character from any other fresh-water group examin- 

 ed by them in Central France, and have so much the aspect of the 

 most ancient secondary rocks, that the presence alone of fluviatile 

 and lacustrine shells, with Gyrogonites, compelled them to recognise 

 the comparitively recent date of the whole group. 



This notice was accompanied by observations on the fossil insects, 

 mentioned in the preceding memoir, by John Curtis, Esq., F.L.S. 

 These insects are all of European forms, and are most of them re- 

 ferrible to existing genera. The greater portions belong to the orders 

 Diptera and Hemiptera; the Coleoptera are next in number, there 

 are only a few Hymenoptera, and but one' Lepidopterous insect. 

 " As a larger collection," says Mr. Curtis, "might greatly change 

 the proportion of the different orders, no positive inference, as to 

 climate, should be drawn from the present assemblage ; but there 

 is nothing in the character of the insects to warrant the supposi- 

 tion of a higher temperature than that of the South of France." The 

 great portion of these remains were very probably brought together 

 from different localities by floods, mountain-torrents, or rivers ; yet 

 there is no insect among them that might not be found in a moist 

 wood. The antennae, tarsi, and other parts whereby the characters 

 would be best distinguished, are often wanting ; yet enough cha- 

 racters frequently remain even then to distinguish the genus. The 

 sculpture, and even some degree of colouring, are preserved in several 

 specimens. The wings of some beetles are extended beyond the 

 elytra, showing that when they perished, they were flying or attempt- 

 ing to escape by flight. 



A collection of fossil vegetables, from the Northumberland and Dur- 

 ham coal-field, was exhibited at this meeting, and presented to the 



