FROM WEST COAST OF SCOTLAND AND THE IRISH SEA. 29 



depth o£ 80 fatbs., had a fair number o£ large Copepoda, mixed, however, 

 with Diatoms (Rhizosolenia semispina, Clicetoceros horeale, &c.)^ Peridinians, 

 and some smaller Copepoda. Another haul in the same spot in 1907 is of 

 the same nature, with a still larger proportion of the smaller Copepoda 

 (mainly P seudocalanus elongatus and Oithona similis) and their Nauplii. 

 One in the Sound of Bute from a depth of 95 faths., on July 30th, 1908, 

 had along with the Calanoids, and some smaller Copepoda, a very large 

 number of Diatoms (chiefly species of Rliizosolenia), so as to be almost a 

 phyto-plankton in appearance. Two hauls taken south of Holy Island, 

 Arran, from 54 faths., in 1908, show also a mixed plankton, consisting of 

 Diatoms aud Peridinians along with the Copepoda. A haul from 80 faths. 



Fjg. 4. — Samples of Phyto-plankton from the Irish Sea, 

 about the time of the Ternal maximum. 



in Kilbrennan Sound on the west of Arran, on July 26th, 1907, consists of a 

 coarse zoo-plankton, in which, however, there are many small Copepoda 

 (^P seudocalanus and Oithona) and other animals {Oikopleura and larval 

 forms) and a few Peridinians and Diatoms {Rliizosolenia semispina), mixed 

 with the large Calanoid Copepods. 



There are four vertical hauls taken in 1908 and 1910 off Ardmore, Mull, 

 in the centre of the channel between Mull and Ardnamurchan. These and 

 a vertical haul taken in the neighbouring Loch Sunart, in 1910^ are all alike 

 in general character, consisting of a fine greenish phyto-plankton mixed with 

 some small Copepoda and a few Oikopleura. The Diatoms are, in all cases, 

 mostly species of Chcetoceros {C. contortum and C. decipiens) and of 

 Thalassiosira (7. gravida and 2\ Xoi'denshioldii). 



