POST-TERTIARY FOSSILIFEROUS DEPOSITS. 25 



2. Laminated clay (not to be distinguished physically from the laminated clay of the 

 Paisley and other sections). 



3. Clay, charged with an Arctic fauna. 



Just as the district around Paisley and other points where the laminated clay 

 occurs would, from their natural position, receive a body of fresh M^ater, supposing the 

 land during the Glacial Epoch more elevated than at present ; so would the district near 

 Christiania, at which the same laminated clay is found. 



Whatever its origin, it constitutes a curiously distinct deposit ; and is easily distin- 

 guishable from the fine clay (sometimes itself called " fine laminated clay " or " glacial 

 marine bed ") which succeeds it, and represents the shghtly moi-e recent bed of an arctic 

 sea, crowded with life. 



The following Ostracoda have been found in the laminated clay : 



Cytheridea puncHUata, Brady. 

 Cytherura Sarsii, Brady. 



§ III. OSTRACODIFEROUS BEDS. 



A. — We proceed to notice in detail the principal beds of clay and sand, characterised 

 by an Arctic Fauna, from which the Ostracoda described in this Monograph have been 

 derived. 



1. Paisley. 



In studying various clay-pits exposed from time to time in the neighbourhood of 

 Paisley, we have observed the following beds, the measurements of .which varied even 

 within a few hundred yards. 



The Boulder Clay is of the usual irregular character, rising up in hillocks here and 

 there, to and above the ordinary surface-level ; and in som-e places formed into troughs 

 of considerable depths. 



1. Surface soil. 



2. Sands and gravels (probably old river-drift). 



3. Littoral marine shell bed, containing Cardium edule, Mytilus edulis, and pieces of wood 

 bored by Teredo, &c. (In one section which we measured this bed was nine inches in depth.) 



4. Marine fossiliferous clay : 



a. Upper part ; no Mollusca to be found, but Foraminifera and Ostracoda. 



b. Middle part ; a few Mollusca, Ostracoda and Foraminifera more plentiful. 



c. Lower part ; fauna abundant. 



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