474 Reviews — M. J. Barrande' s Bohemian Brachiopoda. 



palaeontologist. In a word, the "Faune Calcaire Carbonifere de 

 la Belgique," with the Silurian System of M. Barrande, and the 

 " Jura Normand " of M. Eugene Deslongchamps, may be taken as 

 excellent illustrations of the method adopted by foreign authors as 

 historians, not of one especial group of organisms, but of the physical 

 characters and complete fauna of an entire geological formation. By 

 this means local variations in general physical conditions are duly 

 recognized, and uniformity of geological grouping and zoological 

 classification is secured. No English works of a similar nature can 

 rival those above cited in excellence of palasontological illustration, 

 save the decades of the Survey, or the volumes of our Palaeon- 

 tographical Society. A. C. 



III. — Brachiopodes Etudes Locales. Par Joachim Barrande. 

 8vo. pp. 335, and 7 Planches. (Prague, 1879.) 



WE have here another of those excellent memoirs in which M. 

 Barrande reviews his former labours in the same field ; an 

 epitome, in fact, of those lengthened researches, the results of which 

 are embodied in his classical volumes on the Silurian system of 

 Bohemia. To the student these most instructive resumes are in- 

 valuable as an author's summary of his own investigations, affording 

 information on important points, with references to the exact locale 

 of further details. They furnish the author at the same time with 

 an opportunity for revision and addition, rendered necessary by in- 

 creased discoveries, and for drawing those inferences and conclusions 

 which he is necessarily best qualified to supply. 



Although only two species of Brachiopods were known in 

 Bohemia prior to 1840, M. Barrande now transmits about six 

 hundred and forty named Silurian species to his successors. A 

 number which illustrates the exceptional richness of the Bohemian 

 deposits, and the thorough investigations to which they have been 

 subjected through the energy and laborious industry of the author. 

 It considerably exceeds Mr. Davidson's provisional estimate of 210 

 species from the British Silurian rocks, and almost amounts to half 

 that given by Dr. Bigsby (1422) in his " Thesaurus Siluricus " as 

 the approximate total of known species from the Silurian deposits 

 of the world. Only two of the Bohemian forms are primordial, 

 124 occur in the second zone, and 521 in the third. Thirty-nine are 

 common to France, and forty-two to the " Septentrional " zone of 

 Europe and America. Three new genera, Clorinda, Mimulus, and 

 Paterula, all Secondary, or local types, are added. 



In this memoir M. Barrande gives some very interesting and 

 novel facts concerning the variations observed in Bohemian forms, 

 treats of their vertical distribution, and specific relations with those 

 of other Palaeozoic areas. Thus, it would appear from these 

 researches that neither longevity of type nor the fecundity of a 

 species can be considered as the primary cause of variability. For the 

 long-lived forms often exhibit but few variations, while a species 

 but sparsely represented may be accompanied by numerous ex- 



