198 E. VANDEN EROEOK ON SOME PLEISTOCENE EORAMINIEERA. 



North Atlantic or in the Arctic Ocean. Almost all are also found 

 living in the Mediterranean ; but the presence of Lagena, of 

 Nonionina depressula, and Cassidulina laevigata (which last does not 

 appear really at home except in the colder waters of the North 

 Atlantic, and is very rarely found in the Mediterranean) indicates 

 closer relations with the Northern Oceanic fauna than with that of 

 the warmer Mediterranean. The fauna of the Subapennines in- 

 cludes, besides the greater part of the species of our short list, a 

 moderate proportion of extinct forms of special and characteristic 

 species, of which no representative is here found. 



"With some exceptions, such as Rotalia Beccarii, these Foramini- 

 fera from Ischia are generally of small size, and appear to have lived 

 in conditions but little favourable to their development. It is 

 known that in the greater part of the Pliocene beds of Italy it is 

 entirely different ; the Foraminifera are there mostly large and very 

 well developed ; certain species in these beds are even remarkable 

 for the size that they attain (Nodosaria, Dentalina, and Cristellaria 

 for example). 



Although the lithological nature of the deposit does not indicate 

 littoral conditions, the depth of the water need not, however, have 

 been very great ; for we find among the Foraminifera of this marl 

 most of the species that are generally found in littoral deposits of 

 the existing seas. Such are specially the three Lagena, Planor- 

 buJina mediterranensis, Truncatulina lobulata, Rotalia Beccarii, 

 the Nonionince, and the Polystomellce. 



To return to the marl of Monte Buceto, it is, without doubt, more 

 recent than the true Subapennine deposits ; and on the one hand 

 the small size of the specimens, and on the other the predominance 

 of certain northern forms, would seem to indicate a climate less 

 favourable than that now enjoyed in the Mediterranean. Hence we 

 are led to believe that the marl was deposited when the influence 

 of the great refrigeration of the glaciers had begun to be felt. 



