A CARBONIFEROUS FAUNA FROM NOWAJA SEMLJA. 177 



Its ornamentation distinguishes it from Loxonema ? buccinoideum de Koninck (loc. 

 cit., 1881, pi. vi. figs. 12-13), a species of doubtful generic affinities but of a similar 

 shape, as is also Loxonema semicostatum de Koninck \non Meek and Worthen]. 



LlTTORINIL\E. 



Genus Turbonitella de Koninck. 



Turbonitella biserialis (Phillips). (PL II. figs. 47, 47a.) 



Phillips, Geology of Yorkshire, pi. xiii. figs. 10, 11. 



This species is represented by four small specimens, the largest of which is only 5*5 mm. 

 in length. The small ones have the ornamentation of Phillips' Turbo semisulcatus 

 {loc. cit,, fig. 10), and the greater portion of the last whorl of the largest one has the 

 two sets of alternating ribs as typically developed in Turbo biserialis (loc. cit., fig. 11), 

 its beginning showing the transition of the " semisulcatus " type to the " biserialis " 

 type. This is also exhibited on the end of the last whorl of the intermediate specimen. 



Genus Portlockia de Koninck. 



Portlockia lacordairei ? (de Koninck). 

 De Koninck, loc. cit., 1883, pi. xxv. figs. 17-19. 



Portlockia parallela ? (Phillips). 

 Phillips, Geology of Yorkshire, pi. xvi. fig. 8. 

 Each of these two species seems to be represented by a fairly complete but ex- 

 tremely minute specimen, in all respects like the west of Europe form, except in size. 



Capulhle. 

 Genus Orthonychia Hall. 



Orthonychia sp. (PL II. figs. 39, 39a.) 



Without expressing an opinion as to the value of the generic term Orthonychia, I 

 place under it a very small (6 mm. from apex to frontal margin) capuliform shell which 

 exhibits the features said to be characteristic of 'the genus, that is to say, the apex is 

 incurved to a slight extent only, and shows no tendency to be spirally enrolled. Its 

 specific characters are as follows : — The slopes are steep and meet under an acute angle 

 forming a ridge bordered on each side by a very faint carina ; a shallow groove extends 

 from the apex to the margin, and divides the left side into two equal portions ; this 

 groove is apparently absent on the right side ; the surface is covered with undulating 

 lines of growth. 



