NOTES ON DINOFLAGELLATES. 19 



In two of the experiments A. herdmani was the species 

 used. In each case a bucketful of sand, with its contained 

 organisms, was transferred from the flourishing patch just 

 south of the stream to a position only a few yards away on the 

 north side of the stream (see Map), where the conditions were 

 apparently similar. A healthy culture of the same species, 

 which had been kept in the laboratory for ten days, was also 

 transplanted to the north bank of the stream. In each case 

 the transplanted patch had either disappeared completely by 

 the next day or was present in a reduced and unhealthy state, 

 and dwindled to nothing in three or four days. 



A. kofoidi was also transplanted to the nearest point on 

 the north side of the stream, but, although the discolouration 

 due to this species was intense on the south side for the next 

 few days, no further sign of the transplanted patch could be 

 found. 



Observations made during the spring of 1922 (March 22nd 

 to April 23rd inclusive) revealed nothing new except the unusual 

 scarcity of all kinds of shore-living dinoflagellates. The 

 discolouration of the shore was slight and due almost entirely to 

 small diatoms. While the dinoflagellate population was poor 

 in numbers, it was, however, very rich, for the time of the year, 

 in species. All the Diniferidea mentioned below, except 

 Amphidinium eludens, Polykrikos schwarzi, and Noctiluca 

 scintillans, were represented by a few individuals. 



The following dinoflagellates were observed at Port Erin 

 during 1921 and the spring of 1922. 



Adiniferidea. 

 Wxuviella lima (Ehrbg.) Butschli. Prorocentrum micans, Ehrbg. 



Diniferidea. 

 Amphidinium, asymmetricum, Kofoid, var. britannicum, var. nov. 

 A. asymmetricum, Kofoid, var. compact inn, var. nov. 

 A. eludens, sp. nov. .!. scissum, Kofoid. 



A. herdmani, Kofoid. Oymnodmium agile, Kofoid. 



A. klebsi, Kofoid. Q. placidum, sp. nov. 



A. kofoidi, sp. nov. Polykrikos schwarzi, Bvitschli. 



.1. kofoidi. sp. nov., var. peta8atum var. now Noctiluca scintillans, Macartney. 



