Reviews — £arra)ide's Silurian System, Bohemia. 129 



same horizon. LopJiospira is represented by six species, all from the 

 Oi'dovician (d4 and d5). Two of these are identified with the 

 American L. medialis, Ulrich & Scofield, and Z. tropidophora, Meek. 



Only two species of the Pleurotomariidee are mentioned as common 

 to Britain. One of these from the Silurian (e2) is referred to 

 P. Lloydii, Sow., which occurs also in Gothland, and is placed in 

 the genus Phanerotrema, Fischer, by Perner. It shows a different 

 structure above the band, but seems too badly preserved for accurate 

 determination. The other is referred with a query to P. [Bemhexia ?) 

 Champernoioni (?), Whidborne, sp. It is merely an internal mould, so 

 there can be still less certainty about its identification. 



Perner also places in the family Pleui'otomariidae the genera 

 Sienoloron, (Ehlert, Catanostoma, Sandberger, and Affnesta, de Koninck, 

 though he does not regard them as belonging to Pleurotomaria, s.l. 



Stenoloron contains two new species, -S. pollens, Barr. (f2), and 

 S. amhigena, Barr. (e2), which are especially interesting for showing 

 distinct traces of the very narrow grooved band, which had evidently 

 possessed orifices along it at unequal distances represented by a row of 

 elongated tubercles. 



The Murchisoniidse are divided by Perner into four genera, viz., 

 Pseudomurchisonia, Koken, Murchiso7tia, d'Arcli. & de Vern., s.l., 

 Sinufipira, n.g., and JEctomaria, Koken. Murchisonia, s.l., he sub- 

 divides into eleven subgenera, of which five are new. The other 

 three genera are distinguished from Murchisonia, s.str., by having 

 a sinus and not a slit in the outer lip, and by not possessing a distinct 

 band on all the whorls ; indeed, the two last-named have no band, 

 and Pseudomurchisonia (which is represented by one species) has 

 a band on the later whorls only. 



The new genus Sinuspira (which is also represented by only one 

 species) is particularly interesting in that it apparently forms a link 

 between Murchisonia and Loxonema ; the lines of growth make a deep 

 tongue-shaped sinus without anj* interruption in their course to form 

 a band. Thus it comes near those species of Loxonema which have 

 very sharply sinuated lines of growth, but it may be distinguished by 

 the sinus being of greater depth, and the whorls being more convex 

 and not adpressed at the suture. 



Among the new subgenera Leptorima may be mentioned as remark- 

 able for having a narrow deep band situated between two swellings 

 high up on the whorl just below the upper suture. Ponaldiella, 

 Cossmann ( Ooniospira, Donald), is but doubtfully represented by two 

 species, neither of which has so prominent a band as the type. 

 Ptychocaulus, n.g., of which the type is the well-known Murchisonia 

 Verneuili, Barr. (MS.), is distinguished by the peculiarity of a fold 

 on the columella clearly shown by well-drawn sections of the shell. 

 Another interesting feature in the Murchisoniidse is pointed out by 

 Perner, namely, the fact of the upper part of the spire being partitioned 

 off in several instances. 



The Murchisoniidse range from the Ordovician (D-d5) up to the 

 Middle Devonian (G-gl). 



Previous authors such as Koken, Ulrich, and Scofield differ 

 greatly in the genera they include in the family Euomphalidse, 



DECADE V. VOL. V. NO. III. 9 



