IN THE MUD OF THE LEVANT. 89 



veous matter from the shells of Entomostraca, 

 which are often exceedingly abundant ; especially 

 in strata connected with the Carboniferous era.* 



From the above series of facts some important 

 general conclusions may be drawn. 



As geologists have long been aware, the 

 bed of the Levant consists of an extensive 

 calcareous deposit, now in process of forma- 

 tion, which deposit is known to extend into 

 the Adriatic, and, in all probability, also into 

 the western parts of the great Mediterranean 

 basin. It appears that this deposit consists mainly, 

 if not entirely, of minute forms of organised struc- 

 tures. Some of these are apparently vegetables, 

 belonging to the siliceous group of Diatomaceae. 

 Some are of still more questionable affinities, as 

 spicula of sponges, and the siliceous cases of 

 organisms considered, by Ehrenberg, to be Infuso- 

 ria, — Naviculaceae, Coscinodisci, and Actynocycli ; 

 others are undoubtedly animals, as Foramini- 



* Why these Entomostraca should so often be referred to 

 as indicating the existence of fresh-water, I am puzzled to 

 understand. They are much more abundant in the sea than 

 in anv of our lakes and rivers. 



