128 Reviewi — Ban-ancle h Silurian S;/sfem, Bohemia. 



Tome ii describes rnanj" of the most interesting families, which 

 are 13 in number and contain 105 genera, comprising 326 species and 

 varieties. Tlius we have a total in the two volumes of 133 genera and 

 479 species. In addition 147 other Gasteropoda are mentioned whose 

 state of preservation does not admit of their being referred with 

 certainty to any species or even genus. 



Tome iii will contain the descriptions of five more families, 

 comprising among others many species already figured in tome ii. 

 The Capulidse may be mentioned as an instance of this, 52 plates in 

 tome ii being exclusively devoted to that family. The same volume 

 will also furnish more particulars about the relationships between the 

 Gasteropoda of Bohemia and those of other countries. 



The families described in tome ii are the Pleurotomariidoe, Murchi- 

 soniidae, Euomphalidae, Trochoturbinidae, Delphinulidae, Neritopsidse, 

 Solariidae, Scalaridse, Littorinidse, Loxonematidse, Tumtellidae, Chem- 

 nitziidoe, Subulitidae. Of these the Pleurotomariidte ought by rights 

 to have been described in tome i as the first family of the Khipido- 

 giossa, but as the plates destined for that part contained but few 

 members of the family Perner thought it better to give the Bellero- 

 phontidae the precedence. 



There is considerable difference of opinion among palaeontologists 

 with regard to the respective limits of the families Pleurotomariidae 

 and Murchisoniidae, Koken. Perner considers the form of the 

 aperture the most important feature to be taken into account. Thus 

 shells with more or less rounded aperture he places in the former 

 familj", and those with an oval aperture prolonged into a short canal 

 in the latter. The possession of a nacreous inner layer, or of an 

 elongated forpa, he regards merely of generic value. Both the 

 Murchisonia, d'Arch. & de Yern., and Pleurotomaria, Sow., should 

 strictly possess a slit in the outer lip, the filling up of which during 

 growth gives rise to the formation of a band on all the whorls. 

 Perner states that if Pleurotomaria be restricted to forms agreeing 

 with the Mesozoic types, P. anglica, Sowerby, and P. tuberculosa, 

 Def ranee, it is not represented in the Palaeozoic rocks of Bohemia. 

 But he nevertheless considers that there exist several groups with 

 certain features in common which may be placed with Pleurotomaria 

 (taken in a more extended sense) in the family Pleurotomariidae, and 

 many of these have merely a sinus and not a slit in the outer lip. 

 These groups he regards as constituting genera and subgenera; they 

 number twenty-five, twelve of which are new, and most of the species 

 are also new. Some of the old genera are extended so as to include 

 more species, while others are restricted. Among the latter is 

 Lophospira, of which the types given by Whitfield are L. bicincta. 

 Hall, and L. helideres, Whitfield. Ulrich considerably extended this 

 genus, dividing it into numerous sections ; Perner, however, resti'icts 

 it to the perangulata section of Ulrich, of which L. perangulata. Hall, 

 is the type. He includes some of TJlrich's species of Lophospira 

 in Worthenia, de Kon., and he creates a new genus, Coronilla, for the 

 robusta section of Ulrich, of which P. robusta, Lindstr., is the tj'pe. 

 In the latter genus he gives four new species, all from the Upper 

 Silurian (e2). In IVortJmiia he has also four new species from the 



