33 
require very deep and salt water and are, consequently, found in 
smaller quantities and are probably to be considered as mere 
guests even in the deepest parts of the coastal area. 
Sagitta elegans Verrill. 
Sagitta elegans Verrill 1873, p. 626. 
forma arctica Aurivillius. 
Sagitta arctica Aurivillius 1896, p. 188. 
—  bipunctata f. arctica Ritter-Zåhony 1910, p. 255—264. 
— elegans f. arctica Rilter-Zahony Tora, p. 12: 
Sagitta elegans occurs in the coastal areas of the northern 
Atlantic and in the arctic waters from Smith Sound to the Kara 
Sea. It is also found in the Bering Strait and has, therefore, prob- 
ably a circumpolar distribution though it has not yet been found 
off the northern coast of Siberia, an area hitherto very deficiently 
investigated. It is difficult to state exactly the distribution of the 
Species, as it-has frequently been confounded with other species, 
particularly bipunctata Q. G. The relations between Sagitta elegans, 
bipunctata, and setosa have been dealt with thoroughly by Rit- 
ter-Zåhony (1911a, p. 15 and 16). As the probable southern 
limit of the distribution in the Atlantic he regards the limit be- 
tween the Labrador and the Florida Currents in the west, the Bay 
of Biscay in the east. — Fowler (1906) has also pointed out 
the probability that different species have been confounded under 
the name of bipunctata, and he remarks (p. 68), that if the records 
in the literature were correct, S. bipunctata would be "the most 
" eurythermal, euryhaline, and cosmopolitan organism known". 
The forma arctica is distinguished from the other varieties 
particularly by its considerable size and the comparatively short 
tall. It is widely distributed within the arctic seas and occurs, 
Moreover, in the deep parts of the Skagerak. It is the only species 
among the chaetognaths of the arctic region which has its prin- 
Cipal occurrence in the neighborhood of the coasts. Aurivillius 
(1896) records it as occurring in crowds at the surface in the 
Davis Strait and Baffin Bay between Lat. 647 45' and 749 N., and 
according to Moss (1879) Sagittæ very like bipunctala were 
Common in the morth water of Smith's Sound and in the Baffin 
Vidensk, Medd. fra Dansk naturh. Foren. Bd. 69. 3 
