Reviews — Barrande's Cephalopoda of Bohemia. 361 



chapters Mr. Skertclily supplements the detailed accounts which he 

 gave in his official work, with an amplification of the general results, 

 which are written so as to interest the ordinary reader as well as to 

 furnish food for the geologist. We mufft content ourselves with 

 briefly indicating some of the many subjects treated here, which are 

 of special interest to our readers, such are the history of the present 

 indigenous fauna, and of that of pre-historic times, the migration and 

 diffusion of species, the causes of changes of Climate. The growth 

 of Peat, the question of Water Supply, and the subject of Climate and 

 Disease will suggest many topics of interest. Among the subjects 

 more likely to raise discussion are those connected with the formation 

 of the Chalky Boulder-clay, the alternation of Glacial and Interglacial 

 beds, the Paleolithic gravels, and the age of the Brandon Beds. 

 The entire subject is however rich with interest, and the authors 

 have evidently spared no pains and no expense to render their work 

 as complete in every respect as possible. 



III. — Cephalopodes. Etudes Generales; extraits du Systeme 

 SiLURiEN DU Centre de la Boheme. Par Joachim Barrande. 

 8vo. pp. 253, 4 plates. (Prague and Paris, 1877.) 



BARRANDE has completed his magnificent work on Palaeozoic 

 Cephalopods. Commenced in 1865 with the publication of the 

 first series of his plates, and continued at irregular intervals but 

 without interruption up to nearly the close of last year, this splendid 

 contribution to science extends to 544 large 4to, beautifully executed 

 plates, and to about 3600 pages 4to. of letterpress. 



In the smaller publication we now refer to more especially, 

 Barrande has given us short extracts from the concluding chapters 

 of his work, or those including his " General Considerations of the 

 Cephalopods," and has produced, as it were, a brief summary of the 

 ably reasoned arguments given more in detail in the larger, work, 

 so that an excellent general idea may be quickly obtained of the 

 more important conclusions at which he has arrived. From the 

 character of the publication, it will be obvious that it would be 

 impossible to condense into a few lines, for which alone we can 

 find space here, what is already a highly condensed summary of 

 detailed and close reasonings. In his chapter xvii. the reader will 

 find a most interesting resume of all previous researches on the 

 initial form of the Nautilidce, the Goniatidce and the AmmonitidcB, in 

 which the position, form, size, origin and object of the cicatrix on 

 the initial cowl of the shells, are fully considered, and the remark- 

 able contrasts offered in these respects in the different groups. He 

 then winds up this chapter with some considerations on the chron- 

 ology of the groups, and finally a brief statement of all his con- 

 clusions on the initial forms of the Cephalopods. As to the vertical 

 and horizontal distribution of the Cephalopoda in Silurian countries, 

 it seems established, that this order has appeared suddenly, and for 

 the first time, at the commencement of the second fauna. At that 

 time the only Cephalopods belonged solely to types of the one 



