242 
their proximal half. The proximal end is obliquely cut off; an 
accessory piece, triangular isosceles, is found (fig. 3). 
It is beyond doubt that this form, just as the other members 
of the genus Rhabditis , is a nematode of putrefaction. They con- 
gregate where seaweed, probably also see-animals lie rotting. 
Immediately after the material was collected it contained apparently 
no Rhabditides; it is impossible that I should not have observed 
this large form if it had been present in a tolerable number; 
probably some larvæ must have been present, but at any rate 
their number was so little prominent that they were not observed 
under the examination. First when the material had been standing 
for some time in my room in a glass-cup and I examined it anew, 
it proved to be swarming with Rhabditis mai'ina in all stages of 
development, in short, that I had got a culture of this species. 
However a culture is not always so easily to be got. I have 
attempted it several times with a negative result; and a culture so 
beautifully developed as the first time I have not later succeeded 
in getting. 
Zeiss Okularmikrometer A. O c. 2. 
01 d fe male: Youngfemale: 
Length 195 = 3,1 mm. Length 100 = 1,6 mm. 
Oes. 24. 
Yulva 100. 
Tail 10. 
Width 8. 
Oes. 18. 
Yulva 55. 
Tail 6. 
Width 5. 
Male: 
Length 100 = 1,6 mm. 
Oes. 16. 
Width 4. 
For the old female de Man’s formula gives: a = 24, ft = 8, 
y = 19 1 / 2 . 
Aphelenchus sp. 
All that I know about the genus Aphelenchus is that one 
species oceurs in Denmark. A female was taken in the Kildeskov 
