GEOGEAPHICAL DISTRIBUTION, ETC. 285 



well be classed with terrigenous deposits, on Hceount 

 of its proximity to the land. 



lU'd Clay. — -The Foraminifera of the Eed Clay 

 deposits of the ' Challenger ' collection have been 

 enumerated by Brady, who records 18'2 species. The 

 fauna, as a whole, consists largely of pelagic species, 

 with an admixture of arenaceous deep-sea forms. A 

 conspicuous feature of some of these deposits is the 

 abundance of delicate-shelled Ldf/ciue, many of them 

 exceedingly beautiful in their superficial ornament. 

 Some of the deeper Cilohujeriud oozes, approaching 

 the Red Clays in character, from the Pacific Ocean 

 in the neighbourhood of the Ellice Islands, have 

 been found by the author to contain similar delicate 

 Foraminifera of the same genus. 



Certain of the MilioJiiuc of the Eed Clay deposits 

 have their calcareous tests replaced by a thin siliceous 

 film. 



Terrigenous Deposits. 



The variously coloured Blue, Red, and Green Muds 

 which are found near the coast lines of continents or 

 other land masses, and which almost directly owe 

 their origin to the wearing down of the land surfaces 

 by rivers and the coast line by the action of the 

 waves and tide, possess a foraminiferal fauna some- 

 what peculiar to these accumulations. There is a 

 marked scarcity of calcareous material to be fre- 

 (]uently noticed in the conditions under which they 

 are formed, and this, consequently, has a direct effect 

 on the shell-structure of the organisms found there, 



