102 Transactions of the Royal Canadian Institute 



the surface in August than in the other two months. The data for 

 temperature and salinity at the various depths at these stations on these 

 occasions as given by Vachon (1918, pp. 309 and 311) afford no ground 

 for considering them as factors responsible for the differences in dis- 

 tribution. The time of the day in every case was between noon and 

 mid-afternoon. This does not, however, exclude variation in light from 

 being the factor. In August of that year much fog prevailed in the Bay. 

 The Monthly Record of Meteorological Observations for August 1916 

 records for St. John, N.B., only two days, (15th and 20th), in the latter 

 part of the month as free from fog or rain, and haze and fog were exper- 

 ienced when the hauls were made. On the other hand in September, 

 as given in the Monthly Record for that month, St. John experienced 

 13 days without either rain or fog, and clear weather prevailed when the 

 hauls were made in that month. Likewise during the first week in 

 October the weather was clear. We may, therefore, conclude that the 

 Sagittae are driven to a lower level during clear weather than during 

 foggy or dull weather. 



At "Prince" station no. 5 hauls have been made monthly with few 

 exceptions from May, 1916, up to the present, (December, 1920). For 

 the first two years three hauls were taken each time, one from the 

 bottom to the surface, a tow at a depth of about 20 metres, and another 

 taken just below the surface. In the mild winter of 1916-1917, Sagittae 

 were taken in the surface haul only in January and February. During 

 the severe winter of 1917-1918, they were taken thus in November, 

 December, and March, the ice preventing the hauls being made in 

 January and February. The winter movement toward the surface 

 might be considered as due either to the lessened light or to the lowered 

 temperature. The evidence favours the latter interpretation. The 

 middle of the period when the Sagittae are nearest the surface is about the 

 end of January. This is the time of greatest cold, and much later than 

 the time of least light (December 21). Conversely the Sagittae are deep- 

 est during a period of which the mid-point is in August, approximately 

 the height of summer in the water. 



Horizontal Distribution. 



Although the adult Sagittae are restricted to the deeper waters of 

 the bay, yet as the bay is nearly everywhere comparatively deep, the 

 area occupied by the adults is very extensive, and the total number 

 of individuals, even when not numerous at any one place, is enormous, 

 owing to theii being quite uniformly distributed. During the summer 

 months they are comparatively rare in the tributary bays and estuaries, 

 doubtless owing to the shallowness of these waters. However, when 



