SEA-FISHERIES LABORATORY. 361 



This region west of Mull is, of course, open to the 

 Atlantic south of the island of Tiree (see chart, fig. 1, 

 on p. 369), but whether oceanic plankton is carried in 

 there, or through the wide channel north of Tiree and 

 Coll towards Ardnamurchan and then down the north 

 and west coasts of Mull we cannot say. 



Sound of Mull. 



Two hauls taken in the Sound of Mull between 

 Ardtornish and the Avon B-ock late in August (24th) 

 show a well-marked phyto-plankton of mixed neritic and 

 oceanic type. We print here the vertical haul, showing 

 that it is mainly composed of neritic Diatoms with the 

 addition of some oceanic animals. 



Aug. 24th, 1912. 



Between Ardtornish and Avon Rock. 72 fathoms. 



Calanus fmmarchicus 175 



Pseudocalanus elongatus 5,600 



Acartia clausi 1,250 



Oithona similis 600 



Nauplii 12,500 



Thysanoessa raschii 1 



Decapod larvae 2 



Sagitta bipunctata 10 



Medusoids 5 



Pleurobrachia pileus 1 



Tintinnidae 1,900 



Peridinium spp 5,000 



Ceratium f usus 2,000 



Chaetoceras boreale 5,000 



debile 11,250 



„ decipiens 8,100 



schuttii 9,400 



spp 70,600 



Eucampia zodiacus 14,400 



Lauderia borealis 3,100 



Rhizosolenia shrubsolei 3,750 



stolterfothii 4,400 



The surface gathering taken immediately after the 

 vertical haul is distinctly a phyto-plankton, mainly 

 composed of species of Chaetoceras and Rhizosolenia. It 

 is probable, then, that Calanus and the other oceanic 



