M. Desnoyers 07t the Chalk of the Cotentin. 253 



gence and design with the works so wisely designed. Conse- 

 quently, we do not require, nor ought we to assume, the ex- 

 istence of a principle of life, in addition to the all-intelligent, 

 all-designing, and only living hand. Such an assumption be- 

 wilders the mind, by turning it out of its natural and proper 

 course, and causes Science, the golden fruit of its labours ! ! ! 

 to scatter its seeds over the barren fields of mysticism and in- 

 credulity. 



XLIII. Collections in Foreign Geology. — [No. IV.] By 

 H. T. De la Beche, Esq. F.R., L., and G.S. ^c. S^c. 



[Continued from page 176.] 

 11. On the Chalk of the Coteyitin; by M. J. Desnoyers*. 

 Chalk Formation or Baculite limestone [Calcaire a Baculites), 



SynonyiTies. Banc des Baculites. (De Gerville.) Baculite limestone, Calcaire 

 n Bnculites. (C. Prevost, Defrance, De la Beche, de Caumont.) Varieti/ 

 of Falun or Marl. (De Gerville.) 



T^HE common disposition to attribute characters to chalk, 

 -*- even though geologically considered, which in many places 

 only belong to a portion of its upper or middle divisions, such 

 as whiteness, earthy fracture, loose and tufaceous texture, the 

 presence of silicate of iron, or siliceous concretions, feeble 

 traces of which characters are alone visible in the baculite 

 limestone (of the Cotentin), has, doubtless, as yet prevented 

 this rock from being recognized as a complete equivalent of 

 this important foi'mation. 



* Extracted from the author's Mcmoire sur la Craie ct sur les Terrains 

 Tertiaircs du Cotentin, inserted in the Memoires de la Sociite d'Histoire 

 Natm-ellc de Paris, vol. ii. 



The whole of the above memoir is interesting, more particularlj- that 

 part of it here extracted, as it shows the melting together, if I may so 

 express myself, of the chalk and greensands ; that is to say, there is a rock 

 here described which contains the fossils found in both. This fact is of 

 importance, as it shows that we should guard against attaching too much 

 iin[)ortance to some of those divisions made in this class of rocks, derived 

 from their difference in mineralogical structure. M. Desnoyers, in com- 

 mon with some of the continental geologists, seems to include under the 

 head of" Chalk formation," the Upper and Lower Chalk, the Upper Green- 

 sand, the Gault, and the Inferior Greensand of our English series; there is 

 however, occasionally, some little uncertainty as to the latter, which ap- 

 pears sometimes to be separated from, at others included in, the Chalk for- 

 mation. He this as it may, the Baculite limestone of this part of Normandy 

 is a good example of the great changes that take place in the mineralogi- 

 cal character of the more modern rocks in horizontal distances. 



I liave been obliged in some places to condense this extract, in order to 

 accommodate it to the necessary limits ; but have, I believe, omitted no- 

 thing material. — yrarw. 



Reduced 



