19 
Previous authors have frequently mentioned Sagitta hexaptera 
d'Orbigny as occurring in the North Atlantic and in the waters 
round Cape Farewell. I have directed my attention keenly towards 
the possibility of the presence of this species in the material, but 
never found it. Nor does it occur in the North Atlantic material 
of the ,,Ingolff expedition and the ,, Thor", examined by Ritter- 
Zåhony (1914). It seems reasonable, therefore, that this author is 
right, when he believes that all records of this species from the 
North Atlantic are due to confounding with other: species (Ritter- 
Zåhony, 1911b, p. 54—55). Such is the fact, in any case, as to 
the records of Levinsen in "Spolia atlantica" (1885). The ma- 
terial used by Levinsen is in the Zoological Museum of Copen- 
hagen, and I have examined that part of it which was identified 
as "Sagilta hexaptera". Three of the samples were correctly de- 
termined ; they were from the Atlantic between Lat. 30? and 40? 
North. All individuals from localities north of 40? belonged to S. 
maæxima. The mistake is very pardonable, as the species S. maæ- 
ima was not described until 1896, and the material is in an ex- 
tremely bad condition. 
In all samples I have counted the individuals (in very large 
samples only approximately). 
Finally I have examined the state of maturity of the reproduc- 
tive organs as far as such an examination has been possible on the 
material in hand. It has been necessary in several cases to treat 
the specimens with xylol in order to discriminate the stage of dev- 
elopment of the sexual products, and a bad preservation has not 
seldom made any statement of the developmental stage impos- 
sible. — I shall make here a few remarks on the changes of the 
appearance of the reproductive organs during the development of 
the sexual products. 
In young individuals the spermatogonial parts of the testes are 
Seen as two narrow bands along the inner lateral walls of the tail 
segment. The spermatocytes leave the spermatogonial parts and ar- 
range themselves into groupes (fpolyplastes" of Bordås, 1912), 
incompletely separated by the walls and trabecules of a spongiose 
mesh-work in the room of the testes. When the time of maturity 
is approaching, this meshwork with the numerous groups of sperm- 
atocytes fill up the whole room of the tail. At this stage of dev- 
2 
