130 Revietcs — Barrande's Siiioiaii System, Bohemia. 



De Kon., and tliey also give many of tliem the rank of families. 

 Perner considers it best to regard these latter as sub-families of the 

 Euomphalidae, and he divides these sub-families into genera. He 

 states that true members of the Euomphalidae, like the type 

 E. penfangulatus, Sow., do not exist in Bohemia, and that the family 

 takes quite a secondary place in the Gasteropod fauna. Only one new 

 genus is described, comprising one species; it resembles Euomplialopterus, 

 but has certain distinctive features. The family occurs as early as 

 the Ordovician (D-d 17), is most numerous in the Silurian (E-e2), 

 and is only represented by one species in the Devonian (F— f 2). 



He adopts the family Trocho-Turbinidfe. Koken, for shells bearing 

 a certain external resemblance to Trochus or Turho. This group 

 is very extensive in Bohemia, including no less than nineteen new 

 genera and subgenera created by Perner. By far the greater number 

 of species occur in the Silurian (E-e 1 and 2), but one, Trochonema 

 ezcavatum, Barr., is found in the Ordovician (D-d 4), and others range 

 up to the Devonian (F-f2). For the genus of which Euomphalus 

 discors, Sow., is the type he prefers retaining the name Pol'i/troj)is 

 given to it by De Koninck, as it has been so used for twenty years in 

 spite of its preoccupation by Sandberger. In a note to plate 107 

 he states that he did not see Clarke & lluedemann's " Guelph Fauna," 

 where they suggest the name Polemnita, till this work was in the press. 

 Several small families follow such as the Delphinulidse, Fischer, 

 with one new subgenus ; the Neritopsidj©, Fischer, containing only 

 two genera, Naticopsis, M'Coy, with eight species named by Barrande 

 in manuscript, and referred by him to Natica, and Turhonitella, 

 De Kon., with five species, all also of Barrande in manuscript, except 

 one which Perner considers identical with T. TJssheri, Whidborne. 



The suborder Ctenohrancliia, Schweigg, comprises two sections : 

 (1) Pteroglossa, Troschel, containing the Solariidte, Avith two new 

 genera, and the Scalaridse, Chenu, with eight genera, of which four are 

 new; (2) Tsenioglossa, Troschel, in which are grouped the Littorinidae, 

 Gray, Loxonematidse, Koken, Turritellidse, Graj^, Chemnitziidse, Koken, 

 and the Subulitidae, Lindstrom. Among these the families Littorinidfe 

 and Chemnitziidge each contains one new genus, while the Loxonematidae 

 has two new genera, namely, Auriptygma and KatoptycJiia. The 

 former unites some of the characteristics of Naticopsis, Holopea, and 

 Macrochilina. The latter greatly resembles the Triassic Anoptychia, 

 Koken ; each is represented by two species. Auriptygma is confined 

 to the Silurian (E-e 2), and Katoptyckia to the Devonian (F-f2). 

 Only three of the genera into which the family had been previously 

 divided occur in Bohemia. Of these Loxonema, Phillips, comprises the 

 greatest number of species, eleven of which Perner refers to Loxonema, 

 s.str., and nineteen to a new subgenus which he calls Stylonema. 

 None of the species have been previously described, and they range 

 from the Silurian to the Devonian (E, F, and G). He confines 

 Loxonema, s.str., to shells of the type of L. sinuosum, Sow., characterized 

 by having oblique sutures and lines of growth strongly sinuated or 

 almost subangular near the middle of the whorl. Stylonema, on the 

 contrary, has the lines of growth in the main simply curved and 

 seldom sigmoidal, with sutures more nearly horizontal. 



