FOSSIL INFUSORIA IN IRELAND. 355 



to be composed of the bodies represented in fig. 44, of which 

 the long, linear spicula {a) form at least four-fifths. The next 

 most abundant are those marked (b), then (c) ; those marked 

 (d) are still less numerous, and not always seen, though in 

 some of my examinations the portion of fossil in the micro- 

 scope consisted of them chiefly. Occasionally confervoid 

 fragments (e) were seen, and frequently minute annular por- 

 tions (/), while {g) is very rare. These are all the bodies 

 which I have observed ; there was no admixture whatever of 

 unorganized matter, and no medium of cement whatever. 



The spicular bodies (a) are joints of the Diatoma elonga- 

 tum, ( ( Eng. Flora,' vol. v. pt. 1, page 406). This species 

 grows in the utmost abundance in a small drain of clear wa- 

 ter, in the grounds of the Royal Belfast Institution, and its 

 joints in the microscope are seen to be precisely similar to 

 the spicular bodies. When the loricated Infusoria are burn- 

 ed to ashes, the latter are found to be their siliceous coverings 

 unchanged; and the same thing occurs in the Diatoma, as 

 was discovered by De Brebisson and Professor Bailey. 1 On 

 burning the Diatoma elongatum to a red heat, I found it, 

 when cold, to be unchanged in form and appearance, its sharp- 

 ness of outline being equally well defined as before. The 

 Navicula tripunctata I found equally unaffected by heat, as 

 also some other Infusoria with which I am little acquainted. 

 Of the other bodies in the fossil I as yet know nothing more 

 than their appearance ; but I think an examination of the 

 waters in the localities where the deposit is found, would 

 bring them to light in a recent state. 



The deposit which I have now described is evidently of 

 the same description as that found by Professor Bailey in the 

 New World, and analogous to what is found in several pla- 

 ces of the Old ; viz. the Kieselguhr of Franzenbad, and the 

 deposit in peat-bog near the same place, the Bergmehl of 

 Santa Fiora, &c, which are formed of fossil infusorial re- 

 mains. 2 



Belfast, April 30th, 1839. 



1 See paper of the latter on fossil Infusoria discovered in peat-earth at 

 West Point, in Silliman's Journal for October, 1838. 

 2 See Edinburgh New PhilosophicalJournal, for January, 1837, p. 183. 



