326 The Irish Naticralisi. 



northern range; the remainder are widely distributed both 

 north and vsouth of Britain. It will thus be seen that the 

 fauna has a northern, but by no means an arctic aspect. 

 Indeed the absence of such arctic s\)qciqs 2i.s Lcda pcrnula, &c., 

 which usually characterize the Boulder- clay fauna, is worthy 

 of special note. As to the bathymetrical characters of the 

 fauna, a few of the species, such as Solai, Littorina and Pur- 

 pura, are purely littoral ; the majority are such as live in five 

 to twenty fathoms of water : and one or two, such as Lima 

 subaitriculata and Panopxa norvegica usually inhabit a some- 

 what greater depth ; to these last must be added the Cirripede 

 Balanus Hameri. The Foraminifera do not lend themselves to 

 an analysis of this kind, as they occur throughout a much 

 less restricted bathymetrical range ; but the occurrence of 

 forms derived from Secondary rocks is of great importance, 

 and will be referred to later on. 



Among the specimens collected by the workmen were a 

 number of Liassic fossils, most of them striated and polished. 

 The following is a list, arranged according to zones, of the 

 species found ; we are indebted for their determination to Mr, 

 A. H. Foord, F.G.S. :— 



ScHlothelinia ang:ulata, vSclilotli, ") 



Lima grlg^antea, Sow. | 



Cryphaea Incurva, Sow. f Lower Lias. 



Cai^dinla Listeri, Stutch. | 



VEgoceras Portlockii, Wri^lit. J 



Bclemnltes brcviformis, Voltz., var. y| ^^-^^^^^^ ^ 

 Lytoccr'as fimbrlatus, vSow. > 



Mai*poccras bifrons, Brug. f pper Lias. 



Of these, the most abundant was Gryphcta incurva, of which 

 over a dozen specimens were obtained ; of Cardinia Listeri 

 four were found ; of Lima gigantea three ; and of LLarpoccras 

 bifrons two. The most southern exposure of the Liassic 

 system in Ireland is a few miles south-west of Belfast, whence 

 it extends to the northern coasts of Antrim and Derry, the 

 principal exposures being at Larne and Ballintoy. These 

 beds belong to the lower division only, the highest zone 

 noticed by Tate being marked by Bclemnitcs acutus at Larne. 

 It is remarkable therefore to find in the Kill-o'-the-Grange 

 Boulder-clay not only fossils of the Lower Lias, but two 

 species of Middle Lias age, and one, LLarpoccras bifrons, which 

 is characteristic of a particular zone of the Upper Lias. 



