134 



MEDITERRANEAN PROVINCE. 



The Tethyoe are sponges rendered firm by containing 

 numerous needles of flint throughout their sub- 

 stance j of these, one species, T. lyncurium, extends 

 from our West British and Irish coast, along those 

 of Europe, into the Mediterranean ; many others of 

 this tribe have a like distribution. 



There are creatures to be met with in the waters 

 of all seas, and mostly near the marginal line, which 

 are so minute that the aid of the microscope is often 

 required to show the existence of some of them, 

 and which yet occur in such myriads on certain 

 coasts that their remains become, literally, as 

 countless as the sands. These animals are even 

 now but little known, and the names under which 

 they pass have been generally taken from the forms 

 of their shelly structures : these are the Foramini- 

 fera, and the animals are the Ehizopods, closely al- 

 lied to Sponges. 



Such as occur in British seas, of which some sixty 

 species have been noticed, are exceedingly minute, 

 and our knowledge of the class has been mainly 

 derived from Mediterranean species, where both the 

 forms are more varied, and where some attain much 

 larger dimensions. The waters of the Adriatic, in 

 particular, swarm with these creatures, so that an 

 ounce of sand from the coast at Rimini was found 

 to contain no less than 6000 of these organisms. 



M. A. D'Orbigny, the first naturalist who at- 

 tempted to methodize the Foraminifera, recent and 



