221 
Monohystera similis Bitschli. 
1878: Bitscli, p/ 62 TV fg) 30'4— 0 
1884. de Man, p. 40. T. III. fig. 11. 
Referring to the descriptions which Bitschli and de Man' 
have given of the species, I shall point out, that it is frequently 
found in the Ordrup Mose in the pools near the gate which leads 
to Dyrehaven at the house of the ;,Posemand". It lives here 
especially among Lemna trisulca and on the roots of Hydrocharis 
morsus ranæ. It is very agile with characteristic movements; it 
swims by putting the body in a quickly swinging or oscillating 
motion like the larvæ of certain gnats. When it has advanced a 
little in this manner it stops short with the body stretched out 
and lies as dead, till it after a moment resumes its movements in 
the described manner. 
Tripyla papillata Bitschli. 
1873. Bitschli, p. 52. T. VI. fig. 35 a—b. 
1884; de Man, p 47; TV. fø. 19, 
This species has been taken in the Furesø and in the Lyngby 
Sø where it seems to be very common. In the Furesø it occurs on 
the roots of the plants in the edge of the water, in the Lyngby 
Sø it was taken on the roots of Stratiotes aloides. Besides this a 
single specimen was found in damp moss near the bank of a little 
pond in Dyrehaven, near Springforbi. 
Tripyla affinis de Man. 
1884. de Man, p. 48. T, V. fig. 20. 
De Man writes, that this species occurs in ,,die feuchte Erde 
der Wiesen und Marschgrinde"; the Danish localities are all near 
the sea or brackish water. It was taken on the meadow near Øre- 
sund by Hellerup together with Oncholaimus thalassophygas de Man 
and other typical ,,Brackwassernematoden"; other localities are Hunde- 
sted and Lynæs, near the Isefjord, on roots of plants. 
