The C6te-crO)\ France, and the Cotteswold Hills. 569 



development of the Jurassic series. The region has naturally formed 

 the subject of many important memoirs by French geologists, and no 

 one has paid more attention to it than M. Jules Martin, who has 

 carefully examined the palasontology of all the beds. His cabinet 

 contains a large series of fossils from the different Jurassic stages, 

 stratigraphically arranged, and including all the type specimens 

 which he has figured and described in his works. Dr. Wright has 

 had the opportunity of carefully examining this collection, and the 

 result of this examination is here laid before the members of the 

 Cotteswold Club. 



Dr. Wright publishes a valuable table, prepared by M. Martin, of 

 all the stages of the Jurassic rocks exposed in the C6te-d 'Or, where- 

 in are pointed out their lithological characters, and the leading fossils 

 contained in them. Having studied the beds in ascending order, he 

 commences with — 



1. The Eh^tic Beds. — In the C6te-d 'Or these beds are composed 

 of sandstones and marls, with the characteristic Pecten Valoniensis, 

 Avicula contorta, Cardium BJicBticum, Lima prcecursor, and species of 

 Chemnitzia, Anatina, Myophoria, etc. At Macigny they appear to 

 be entirely arenaceous, with beds of arkose ; the whole deposit 

 rests on granite. The same lithological character prevails at Mon- 

 tigny, Semur, and Pouillenay. M. Martin has detected the bone-bed 

 in several localities, — at Savigny, where it appears to occupy the 

 upper part of the Avicula-contorta zone, at Memont, and at Kemilly, 

 where it is interesting to learn the complete transition, both litho- 

 logical and palseontological, which obtains between the Lias and 

 Rhsetic strata. In the West of England, particularly where the 

 white Lias is developed, the junction of these beds is generally 

 well marked, and rather by a change of sedimentary condition than 

 of unconformity. While nothing could be more gradual than the 

 passage upwards of the New Eed Marl (Keuper) into the grey marls 

 of the Ehsetic series. 



A good number of species have been collected from the Avicula- 

 contorta zone in the Cote-d'Or. Of reptiles, two species of Ter- 

 matosaurus ; of fish, 14 sp. ; of Gasteropoda, 8 sp. ; Conchifera, 46 

 sp., etc. Also one Echinoderm, one Coral, a Sponge, two Annelids, 

 and a couple of Plants. The absence of Cephalopoda is marked, and 

 but one species, Belo- (or Geo- ?) teuthis, found by Mr. Boyd Daw- 

 kins in the grey marls at Watchet, has been recorded in this country. 

 Dr. Wright gives some account, with sections, of the British Ehsetic 

 beds. They are well known from his previous publications, and the 

 labours of Messrs. Charles Moore, Bristow, Etheridge, and others. 



2. Lias. — M. Martin divides the Lias into four stages : — 1st. 

 Hettangien or Infra-Lias ; 2nd. Sinemurien or Lias inferieur ; 3rd. 

 Liasien or Lias moyen ; 4th, Toarcien or Lias superieur. The Het- 

 tangien is shown by Dr. Wright to represent the two lower stages of 

 our Lower Lias — the zones of Ammonites angulatus and A planorbis. 

 The Sinemurien comprises two zone^ : a. Bluish marly limestone, 

 with Ammonites oxynotus, A. stellaris, A. Birchii, etc. b. Marls and 

 limestone, with A. bisulcatus (vel BucMandi), A. Scipionianus, and 



