Reviews — Barrande'n Siiurian Si/ste)u, Bohemia. 127 



of the animal kingdom which he had mistaken for Gasteropoda. 

 Barrande drew the figures as the material came to hand during 

 successive years, a practice that involved much repetition. On the 

 one hand he laid stress npon minute distinctions of little moment, 

 while on the other hand important features of detail and ornament to 

 which much value is now attached were sometimes overlooked. To 

 compensate for this latter deficiency Pernor has inti'oduced numerous 

 admirably executed drawings into the text. The indiscriminate 

 mixture of figures has been much more difficult to cope with 

 satisfactorily. Pernor has considered it best to give the descriptions 

 in zoological order, and has in the main followed the classification of 

 Pilsbrj' in the Text-book of Palaeontology by K. A. von Zittel, 

 translated by C. K. Eastman, vol. i, 1900. 



Though tome i contains the descriptions of the families Patellidse, 

 Carpenter, and Bellerophontidse, M'Coy, only, the plates of necessity 

 contain in addition the figui'es of species belonging to many other 

 families. To render these plates comprehensible before their detailed 

 description can be published more than usually full explanations and 

 notes are given. Tome ii also comprises figures of species which 

 cannot be described before the publication of tome iii. Though Pernor 

 has used Barrande's plates, he has not been able to adopt his explana- 

 tions and descriptions, as the real structure of the fossils and their 

 phylogeny were then imperfectly known. He has been obliged to 

 change many both generic and specific names, while adhering as far 

 as possible to Barrande's nomenclature. This was all the more 

 advisable as Barrande made out preparatory tables of genera and 

 species which he named provisionally, and he also presented specimens 

 to many European collections with his manuscript names attached. 



In chapter 1 (tome i) Pernor gives a chronological list of some forty- 

 three works in which Bohemian species of Gasteropoda have been quoted. 

 Amongst them is Bigsby's "Thesaurus Siluricus," 1868, where about 

 244 species are recorded whose names were transmitted by Bai'rande. 

 Pernei" considers the Gasteropod fauna of the Bohemian basin more or 

 less peculiar to that area, with the exception of there being an almost 

 complete connection between the Gasteropoda of f 2 (Devonian) and 

 those of the calcareous deposits of Lower Devonian age in other 

 countries. As Barrande's title " Sj^steme Silurien " is somewhat 

 misleading, it may be well here to give a reminder that his etages, 

 D, E, F, G, whose Gasteropoda are described in the volumes before us, 

 include not only the Silurian formation as now understood but also the 

 Ordovician and the Lower and Middle Devonian. 



Pernor divides the families into groups usually differentiated as genera 

 and subgenera, the exact value of which cannot at present be accurately 

 determined owing to the lack of sufficient material. He has, however, 

 found it advisable to divide the family Bellerophontidae, M'Coy, into 

 two larger groups ' in the first instance, and then to subdivide these 

 into genera, laying great stress on the presence or absence of a dorsal 

 band, the first group, Cyrtolitoidea, being devoid of it, while the other, 

 Bucmiioidea, possesses it. This family and the Patellidte, Carpenter, 

 contain respectively 20 and 8 genera and subgenera (some of them new), 

 comprising 153 species and varieties. 



