212 



Proceedings of the Royal Irish Academy. 



Dickie's statement referring to the occurrence of Eed Algae at a depth of 

 80 fathoms must evidently refer to drifted specimens. There are no records 

 of tlie ma>dmum depth at which Algae are found actually growing on the 

 coast of Ireland, but it is extremely improbable that any occur below a 

 depth of 25 fathoms. 



EEVISED CENSUS OF SPECIES. 



A. — Freshavater Species. 





M 



C 



L 



U 



Ireland 



FlageUatae, 



8 



6 







6 



15 



Peridinicae, 



4 



5 



1 



5 



10 



Diatomacouo, 



150 



147 



206 



196 



281 



Cyanophyceae, 



61 



55 



98 



86 



163 



Doamidiaceau, 



293 



360 



282 



323 



499 



Other ConjugaUi-, . 



13 



6 



26 



9 



35 



C'liloro|)liyii'iii-. 



88 



96 



14 li 



118 



24 'J 



lUiodophyceae, 



\ 



3 



10 



6 



11 



Total, 



621 



678 



769 



749 



1263 





Vi 



C 



L 



U 



Ireland 



Fiagcllatac, 



1 







1 



1 



1 



Silicoflagbllatav, 



•■^ 







1 



2 



2 



Coccosphaerales, 











1 







1 



Peridinieae, 



16 







23 



15 



24 



Diatomacene, 



178 



131 



275 



133 



401 



Cyanophyceae, 



18 



7 



29 



10 



31 



Chlorophyccae, 



49 



26 



55 



44 



80 



Phaeopliyceae, 



85 



47 



74 



65 



121 



Rhodophyceae, 



162 



lO.f 



163 



144 



232 



Total, 



511 



314 



622 



414 



893 



