50 



DEPARTMENT OF THE XATAL SERVICE 



Collections were made with more or less regularity tliroug-liout the year at each of 

 the seven stations marked on the appended map: Prince Stations 1, 3, 4, 5, 6, 9, and 10. 

 Particular attention was given to tows taken at Station 6, which it will be noted is at 

 the mouth of the St. Croix river and directly opposite to the Atlantic Biological 

 Station. Here material was obtained with great regularity : at first twice a week and 

 later, when it was ascertained that changes in the content were not rapid, weekly. All 

 collections made were taken in a net of No. 20 sill^ bolting cloth. The same net was 

 used on all occasions, and was towed for twenty minutes behind a boat, the speed of 

 which was kept as uniform as possible for all the tows. Culture material was imme- 

 diately emptied into a large jar of water; material for examination was preserved in 

 two to three per cent formalin. 



Seasonal Distribution and Relative Abundance. 



Station 6. — Tows, as recorded above, were taken twice a week at the surface and 

 at a depth of from 5 to 6 metres during the months of October and November. Later 

 weekly collections were deemed sufficient, a-nd during the winter, material was 

 gathered even less frequently. Owing to a misunderstanding only surface tows were 

 made for a few weeks after the first of May. Enough has been obtained, however, to 

 .give an accurate idea of the monthly possibilities. Tables I to TV give a record of 

 representative five-metre tows throughout the year at Station 6; and from these the 

 gradual increase and disappearance or general constancy of the different forms can 

 be traced. Since, with the counting apparatus employed, it was possible to use only a 



TABLE I. 

 station 6. October — December. 5m. Tows. 



