174 DR G. W. LEE ON 



Pleurotomarid^e. 



Genus Mourlonia de Koninck. 



Mourlonia Isms (M'Coy). (PI. II. figs. 44-446.) 



M'Coy, Synopsis of the Carboniferous Limestone Fossils of Ireland, 1844, p. 41, pi. v. fig. 15. 



This very depressed species appears to be represented by two small specimens 

 measuring 6 mm. in diameter. The slit-band is perhaps slightly wider than is the case 

 in the type-figure. 



Genus Murchisonia d'Archiac and de Verneuil. 



Murchisonia aff. archiaciana de Koninck. (PI. II. fig. 42.) 

 De Koninck, Faune du Galcaire Carbonifere de la Belgique, vol. iv., 1883, p. 16, pi. xxxiv. figs. 5-6, 19-20. 



De Koninck's species was founded on a much larger form. The fragmentary 

 specimen which I compare to it is much smaller, the length of the four whorls com- 

 posing it being only 6*5 mm., and the diameter of the last whorl 3 mm. The tapering 

 is the same as in the Belgian species, and the ornamentation is similar, but there are 

 four keels on each side of the sinual band, whilst in Murchisonia archiaciana four 

 keels are stated to be above the band, and six or seven below it ; the latter are also less 

 pronounced. 



Bellerophontid^e. 



Genus Bellerophon de Montfort. 



Bellerophon hiulcus (Martin). 



J. db C. Sowerby, Mineral (Jonchology, 1825, pi. 470, fig. 1. 



Bellerophon hiulcus is represented by a few specimens, the largest of which does not 

 exceed 12 mm. in diameter. 



Bellerophon aff. tenuifascia J. de C. Sowerby. 



J. de C. Sowekby, Mineral Conchotomy, 1825, pi. 470, figs. 2-3. 



The ornamentation and the fine, thread-like ridge are as in the British species, from 

 which the specimen at hand — measuring 18 mm. in diameter — differs in being less 

 globose, the periphery being somewhat flattened, especially on the last part of the whorl. 



