POST-TERTIARY BEDS OF SCOTLAND. 93 



Cytheridea lacustris (G. 0. Sars). 

 Loxoconcha impressa (Baird). 



' — tamarindus (Jones). 

 Xestoleberis depressa, G. 0. Sars. 

 Cytherura niyrescens (Baird). 



— similis, G. 0. Sars. 



— striata, G. 0. Sars. 



— angulata, Brady. 



— undata, G. 0. Sars. 



— gihha (Midler) . 



— acuticostata, G. 0. Sars. 



— cellulosa (Norman). 

 Cytheropteron latissinmm (Norman). 

 Fseudocythere caudata, G. O. Sars. 

 Sclerochilus contortus (Norman). 

 Paradoxostoma variabile (Baird). 



— abbreviatum, G. 0. Sars. 



— arcuatum, Brady. 



§ IV. GENERAL SEQUENCE OF THE POST-TERTIARY BEDS OF 



SCOTLAND. 



While the place of several individual deposits — the precise nature of the causes by 

 which they were produced — and the subdivisions of the periods to which they may be 

 referred, involve geological arguments beyond the scope of the present paper, it may add 

 to the clearness of those details, distinctive of the beds from which Ostracoda have been 

 derived, and which have been already dwelt upon, to subjoin a reference to the General 

 Sequence of the Post-Tertiary Beds of Scotland. 



In tabulating this general sequence itself, however, we shall confine ourselves 

 almost entirely to points illustrated by our previous descriptions of the several beds with 

 the fauna of which this Monograph is chiefly concerned. 



Without attempting to give anything approaching to a final and complete sequence 

 we simply submit an arrangement, in the direction of which our investigations have led us, 

 for the purpose of furnishing a tentative grouping of a large number of deposits which 

 it is impossible to study when they are miscellaneously intermingled. 



