200 



Scientific Proceedings, Royal Dublin Society. 



air till their examination, which was carried out within two days of the time 

 of gathering. The ohservations were subsequently further extended, and 

 repeated in many cases, with specimens from Dublin Bay collected during 

 November. Owing to the rapidity of bacterial action on these algse, attention 

 to the fresh condition of the material is essential. 



To perform the tests, a portion of the uninjured thallus, or a section of 

 it, was allowed to soak in the reagents a-naphthol and benzidine, whilst 

 for the less permeable guaiacum either a section or a macerated thallus was 

 employed. 



The results obtained up to the present are recorded in the following 

 tables : — 



CataLise 

 reaction 



Oxydase reactions, indirect, with 



Benzidine Guaiacum o-Naphthol 



CHLOEOPHTCE^.i 



Enteromorpha intestinalis. Link., 

 Ulva Lactuca, L., . 

 Cladophora sp., 



PH^ffiOPHYCEa;. 



I. PH^0SP0KEj5i. 



(a) Ectocarpaeea;. 



Chorda filum, Stackh., 

 Desmarestia aculeata, Lamx. 



(i) SphacelttHacece. 



Sphacelaria cirrhosa, C. Ag., . 



(f) Laminariacete. 



Laminaria saccharina, Lamx., . 

 L. digitata, Lamx., . 



II. CyclosporEjE. 

 Fucacece. 



Fucus vesiculosus, L., 



F. serratus, L 



F. platycarpus, L., . 

 Ascophyllum nodosum, Le Jol., 

 Pelvetia canaliculata. Dene. ^- Tin 

 Halidryssiliquosa, iywfj'i.. 



' Oltmann's classification has been followed throughout. 



