CANADIAN FISHERIES EXPEDITION, lOlJflo 



441 



The small individuals of the (iulf Stream stations were taken in abundance at 

 or near the surface at 3 p.m. (station 44), G p.m. (station 74), and 9 p.m. (station 

 75), and these hauls contained mature individuals, thoug-h small. At station 50, two 

 si>ecimens were obtained in the deep closing-net haul below 260 metres, and forty- 

 two from 250 metres to the surface. The records at station 74 and 75 show that 

 nearly as many (21 as opposed to 35) or more (50 x 5 as opposed to 25 x 4) were 

 obtained from the shallow vertical haul (55 — Om.) as from the deep vertical haul 

 (325 — Om.). These facts indicate that the warm-water variety of the Gulf Stream 

 occurs chiefly near the surface, even during the day. 



The large individuals of the colder water are to bo found in the intermediate 

 water (between Gulf Stream and coastal water) where mixing may be supjwsed to be 

 going on. The vertical currents that are doubtless i:)rescnt here would tend to bring 

 them nearer to the surface, and so influence the vertical distribution. 



The mixing would also tend to give the opposite result, namely, fewer aft the 

 surface, when the surface water comes from the cold shallow coastal water, in which 

 S. serratodentata does not occur. However, the records show fairly conclusively that 

 these large individuals do come to the surface at least dTiring the night, num1x?rs 

 having been taken near the surface at 9 p.m. (Acadia Stations 19, 38, 50), at 12 mid- 

 night (Acadia stations 39, 46, 51) at 3 a.m. (Acadia stations 5 and 16), at 6 a.m. 

 (Acadia station 47), and at 9 a.m. (Acadia stations 17 and 85). At no stations taken 

 about the middle of the day were large individuals obtained in numbers, yet si^ecimens 

 were taken near the surface at 12 m. (Acadia station 86) and at 3 p.m. (Acadia stations 

 72 and 87). At Acadia station 50, twenty-seven specimens were caught in the vertical 

 open net from 145 metres to the surface, one in the closing net from 145 to 55 

 metres, eleven in the open vertical net from 55 metres to the surface, and very many 

 at the surface. This would indicate that at 9 p.m. the bulk of the individuals were 

 above 55 metres. On the other hand, at station 51 almost as many were obtained 

 from 125 to 55 metres as from 125 metres to the surface, so that the data are 

 inconclusive. 



In the Laurentian channel at Acadia stations 85, 86, and 87, the vertical hauls 

 indicate that it came very near the surface, but was as abundant in the depths as at 

 the surface, or perhaps more abundant. The three stations gave fourteen in the deep 

 hauls, as compared with three in the shallow hauls. This suggests that it is farced 

 into deeper water by the presence near the surface of water of too low a salinity. If 

 it comes to the surface is spite of the unsuitability of the surface water, it will 

 doubtless perish and thus fail to penetrate as far into the St. La\\Tence gulf at does 

 E. liamaia. 



Individuals a)jove ISmni. in length were obtained at or near the surface at 

 practically evei-y hour of the day. Taking the stations at which these large individuals 

 were obtained, we have the following positive and negative results for the near 

 surface hauls : — 



There can be no doubt that this species is truly epiplanktonic in both cold and 

 warm water, though whether or not it is driven below the surface to any extent. 1)> 

 the light during the day is an open question. 



Horizontal. — S. serratodentata is cosmopolitan, occurring in all oceans except in 

 the far north and the far south. Its most northerly record is 60° 2' N. and 22° 56' W, 



