354 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



As no haul was ever taken with the trawl over this par- 

 ticular area during my cruises, I cannot say what the fauna 

 living on this deposit may be, but, judging from that obtained 

 on the mud-banks off Duddon, it would not be prolific. 

 Although many slides of this mud were examined, no living 

 organism was found in it, but this does not, by any means, 

 prove that it is destitute of life, the negative result which I 

 obtained being probably the result of the dredge giving me a 

 sample of the surface mud only, and I have little doubt that 

 a sample obtained by means of the Lucas Grab would demon- 

 strate the presence of a characteristic fauna. 



The questions now naturally arise — where does this mud 

 come from, and why is it deposited in this particular place, 

 which is surrounded on all sides by the characteristic sand and 

 shell deposits of the North-eastern half of the Irish Sea ? 



In all probability the explanation is to be found in the 

 fact that the general direction of the currents in the Irish 

 Sea is from South to North. Consequently all the 

 minute and easily transported matter brought down by the 

 rivers Mersey and Dee, besides the numerous other smaller 

 streams, is carried in a state of suspension in a Northerly 

 direction, and therefore, wherever there is a slight depression 

 in the sea-floor, sufficient to cause an eddy, this fine mud is 

 thrown down, and so accumulates to form a deposit, such as 

 is found between the Bahama and Selker ships. Two such 

 depressions exist in the area from which these samples were 

 obtained— one on either side of a line drawn from the Bahama 

 to the Selker ships. My samples were taken at a point 

 practically on the Southern lip of the Northern depression, at a 

 depth of about 14 fathoms. 



The peculiar and distinctive odour of this mud is caused 

 by the quantities of decomposing organic matter found in the 

 deposit. I made several smears of the mud, and tested for 

 bacteria by staining with carbol-gentian violet. The result 



