232 transactions liverpool biological society. 



Comparison with Previous Tears. 



We have no data this year representing the Clyde 

 Sea-Area, but can deal with all our previous localities 

 north of Cantyre, as follows : — 



Firth of Lorn. 



Half a dozen hauls, ranging between Sheep Island 

 and the Lynn of Morven — mixed hauls, but on the whole 

 more zooplanktonic than in previous years. The Diatoms 

 are mainly neritic. A haul taken off Lismore on July 

 10th is the only purely phytoplanktonic gathering in this 

 series, and contains about fifteen millions of Chaetoceras. 

 The rest of the hauls from this district were taken a 

 couple of weeks later between the 24th and 26th of July, 

 and it is quite likely that their more zooplanktonic 

 character is due to the seasonal disappearance of the 

 phytoplankton. 



North End of Sound of Mull. 



Hauls at Tobermory show much the same characters 

 as in previous years, but one off Ardmore, on July 11th, 

 presents a striking difference as it is almost a pure zoo- 

 plankton, the Diatoms which were present to the number 

 of over 40 millions per haul the previous year being 

 represented now by only a very few Chaetoceras and 

 Coscinodiscus, about 1600 in all. The details of the 1910 

 and 1911 hauls at this locality are given below for com- 

 parison. It was here, this year, that we first met with 

 the Pteropods (Limacina retroversa) which were so 

 abundant from this point onwards up to the Orkneys. 



Hebridean Sea and Round the Small Islands. 



Fifteen hauls represent this area, and on the whole 

 they are more zooplanktonic than in previous years, and 

 show a change in the nature of the few Diatoms present, 



