CA^'ADIAN FISHERIES EXPEniTIOX, lOl'rto 407 



enough to explore the peculiar bottom water of the deeper portions of the gulf. It has 

 not been thought necessary to refer in every instance to these evident imperfections 

 in the material. 



The tow hauls arc the most unreliable, owing to lack of information in the records 

 as to the manner in which thej' were taken. The depths given are in most instances 

 merely presumptions from the scanty data available. The tow hauls were taken in a 

 great variety of ways. 



There has been a possibility of considerable error arising in counting the speci- 

 mens, for, owing to the large amount of plankton and the short time available for the 

 work, it was necessary in many cases to take only a portion of the catch for examina- 

 tion and for the determination of the number of individuals. A varying portion was 

 taken, depending largely upon the quantity of the plankton and the ninnlu'l- and the 

 range of size of each species. The figures indicate the manner in which the deter- 

 mination was made: 15x10 meaning that 15 individuals were counted in approximately 

 one-tenth of the entire haul. With many of the tow hauls arbitrary signs have been 

 used to indicate roughly the relative number of individuals : x meaning that the species 

 occurred or that only a few specimens could be seen; xx meaning that there were more 

 numerous; + meaning that there were many; and ++ meaning that there were very 

 many. 



There is also a doubt as to proper identification when large numbers are examined 

 rapidly. Errors from these causes have been detected and corrected in a number of 

 instances. Naturally, the larger the individuals the less likelihood is there for such 

 errors to arise. 



2.— ON THE QUANTITY OF PLANKTON OBTAINED AT ONE HFNDRED 

 AND SEVENTY-NINE STATIONS DURING THE CANADIAN FISH- 

 ERIES EXPEDITION, 1915. 



(By A. G. Huntsman, B.A., M.B., Curator of the Atlantic Biological 

 Station, St. Andrews, New Brunswick.) 



At Dr. Hjort's request, I have determined roughly the amount of plankton taken 

 in the various hauls during the cruises of C.G.S. Acadia, C.G.S. Princess, and C.G.S. 

 No. 33. For a number of reasons the data are far from being accurate. The plankton 

 was not measured at the time it was obtained. In most cases all of the plankton was 

 preserved, but at times only a portion was retained and the rest thrown away. In 

 some of these cases (but not all) an estimate was made of the total amount at the time 

 it iwas taken. In other cases the plankton was partially sorted or a portion taken out 

 before being measured. As a result, some of the larger quantities should be still larger, 

 but the smaller quantities are approximately correct. 



The table given below is self-explanatory, but some comment may be advisable. 

 Under " hour " are given the times of commencement and finish of the station as far 

 as the records were kept. When only one time is given, it is the time at which the 

 station was begun. The depth of water is given in metres. When no sounding in 

 metres was made, the sounding in fathoms has been converted into metres for 

 uniformity. 



The hauls of plankton were made in three ways: (1) Vertical hauls (vert.) in 

 which the net was lorwered to a certain depth and then hauled to the surface; (2) 

 vertical closing hauls (vert, clos.), similar but closed some distance before the surface 

 was reached; and (3) toiv hauls (tow), in which the net was towed at a variable dist- 

 ance from the surface. The vertical hauls were not always vertical owing to the 

 drifting of the ships, fwhich in some cases was considerable. The numbers given for the 

 depths of the hauls indicate the amount of wire out, which was occasionally more than 

 the actual depth at the station. In Acadia stations 44 to 91 the vertical hauls were 



