BEITISH ASSOCIATION. 257 



In all the preparations diatomaceous forms were fonnd. Some few 

 were unknown to me, and all the rest were discovered to be identical 

 with existing forms, described by Mr. Smith in his work on the Diato- 

 macese. 



The following is a Table of the species which I found on the slides. 

 I have marked in parentheses whether the species is found in the recent 

 state, in marine, fresh, or brackish water, and this on the authority of 

 Professor Smith's " History of British Diatomaceae." 



Achnanthidium lanceolatum (fresh water) ; Glenarm and Portrush. 

 „ linear e (fresh water) ; Garron Tower and Portrush. 



„ microcephalism (fresh water); Ballyleg Quarry, Glenarm, 



and Portrush. 

 Achnanthes brevipes (fragment), (marine) ; Glenarm. 

 Actinocyclus sedenarius (marine) ; Portrush. 



Amphora minutissima (fresh water) ; Ballyleg Quarry, Glenarm, and 

 Portrush. 

 „ ovalis (fresh water) ; Ballyleg Quarry. 



Biddulpha (?) (fragment), (marine) ; Ballyleg Quarry. 



Cocconeis pediculus (fresh water) ; Ballyleg Quarry, Glenarm, and Port- 

 rush. 

 ,, scutellum (marine) ; Glenarm. 

 Cocconema parvum (fresh water) ; Ballyleg Quarry, Glenarm, and Garron 



Tower. 

 Coscinodiscus radiatus (fragment), (marine) ; Portrush. 

 Cyclotella Kut%ingiana (fresh water) ; Ballyleg Quarry and Glenarm. 

 Diatoma vulgar e (fresh water); Ballyleg Quarry and Glenarm. 

 ,, elongatum (fresh water) ; Glenarm and Garron Tower. 

 Denticula tenuis (fresh water); Glenarm, Garron Tower, and Portrush. 

 Epithemia sorex (fresh or brackish water) ; Glenarm. 

 „ gibba (fresh water) ; Glenarm. 



„ granulata (fresh water) ; Glenarm. 



Gomphonema constrictum (fresh water) ; Ballyleg Quarry and Glenarm. 

 „ dichotomum (fresh water) ; Ballyleg Quarry and Glenarm. 

 „ , , /3 (fresh water) ; Ballyleg Quarry and Glenarm. 



,, acuminatum (fresh water) ; Ballyleg Quarry. 

 Grammatophora marina (marine) ; Ballyleg Quarry. 

 Himantidium pectinate (fresh water) ; Ballyleg Quarry and Glenarm. 

 Melosira variant (fresh water) ; Ballyleg Quarry, Glenarm, and Gar- 

 ron Tower. 

 ,, nummuloides (marine); Ballyleg Quarry. 

 Meridion constrictum (fresh water) ; Ballyleg Quarry. 

 JYavicula crassinervia (fresh water) ; Ballyleg Quarry and Portrush. 



,, didyma (marine) ; Glenarm. 

 Nitzschia minutissima (fresh water) ; Garron Tower. 



„ sigma (fragment) (marine or brackish water) ; Portrush. 

 ,, tenuis (fresh water) ; Ballyleg Quarry and Portrush. 

 Odontidium mutabile (fresh water) ; Glenarm and Garron Tower. 



