CANADIAN FISHERIES EXPEDITION, lOUfla 



433 



Hjort (1912, p. 640) considers that this species (as S. gigantea) is arctic to boreal 

 in its distribution, and has found it as a typical inhabitant of the deep cold water of 

 the Norwegian sea. Apstein (1911, p. 173) records its distribution in European waters 

 as being restricted to the Atlantic and the Norwegian sea, but in one year at least 

 coming down the Norwegian gully to the western part of the Skager-Rack. It was 

 strictly limited to the deep water, remaining below 100 metres. This is very similar 

 to what we have found, the species tending to enter the St. Lawrence gulf along the 

 submerged Laurentian valley. It will probably be found at times well inside the 

 gulf in the deep water. 



The distribution of this species may bo contrasted with that of S. lyra, its closest 

 ally. 8. lyra belongs to the Gulf Stream, but large individuals wander into the north- 

 ern oceanic water *S'. maxima belongs to the northern oceanic water, but small indi- 

 viduals wander into the Gulf Stream. Both species are apparently unfitted for life 

 in water of low salinity like the coastal water, regardless of temperature. 



(e) Sag^tta serratodentata Krohn. Fig. 4. 

 1911. Ritter-Zahony, p. 22. 



Fig. 4. — Sagitta 

 serratodentata. 



The range in size is from 6 to 24m'm. in length. All the larger individuals were 

 sexually mature. The slender build of this species- and the early appearance of the 

 seminal vesicles on either side of the tail, make it easily distinguishable from our other 

 Chaetognaths. A character to which attention does not appear to have been called is 

 the presence in the young of a distinct bridge between the anterior and, posterior fins 

 on each side. This tends to disappear with age. In young individuals the seiTations 

 on the hooks are seen with difiiculty, if at all. The variations in the descriptions of 

 this species, as taken in different localities, make one question whether several species 

 have not been confounded. The great differences in the conditions throughout our 

 waters give us almost the extremes of these variati(ms. In the warm water at Acadia 

 station 44, the largest individuals were only 12mm. long. Both their male and female 

 gonads were mature. The jaws were few (5-8), the tail proportion small (23-27 per 



