SEA-FISHERIES LABORATORY. 353 



The quartz grains are composed, for the most part, of rock 

 crystal and are decidedly angular in appearance, although 

 their edges and corners have been smoothed off. Grains of 

 magnetite or titanoferrite are common, and there are a few 

 pieces of what I take to be hornblende as well. 



The pebbles, which are by no means uncommon, are well 

 polished and water-worn, but as several of them have polyzoan 

 growths on their surfaces it is unlikely that they have undergone 

 much erosion since being deposited in their present position. 



X. [* and 13] 18/2/13 and 16/S/13. Half-way between 

 Bahama Ship and Selker Ship. 



Here we find a deposit of a totally different nature from 

 any hitherto examined. Two samples were obtained from this 

 station, one on February 18th, the other on April 16th. 

 Both seem to be identical and consequently will be considered 

 together. 



These deposits consist of a bluish-grey mud which possesses 

 a peculiarly disagreeable and penetrating odour. When first 

 obtained it is plastic and very sticky, but after standing for 

 a week or two in concentrated formol it assumes the con- 

 sistency of a stiff clay. On examination under the microscope 

 it appears to be made up, for the most part, of grains of quartz 

 of the most minute size as well as diminutive particles of 

 matter evidently of organic origin. The quartz grains vary 

 considerably in size, even in this extraordinarily fine state of 

 comminution. Some are easily distinguishable under the 

 microscope, but the majority are so minute as just to be 

 recognisable and no more. Among the organic constituents 

 were annelid setae, small echinoid spines, the comminuted 

 remains of minute ophiuroid rays, and many particles of 

 zoophytes — all of which might be carried long distances by 

 currents and tides in a state of suspension in the water. 



