250 
f. i. D. stagnalis and perhaps to other genera too, in whick 
the tail of the male is different from that of the female. In the 
month of June a male in moult was taken at the Furesø; the 
animal had the appearance of a female with long pointed tail, but 
the old cuticula contained a fully developed male with the tail 
rounded and with spicules and preanal papillæ. I give a figure of 
my preparation of this specimen (fig. 38); it proves that the young 
male has the shape of a female till maturation. 
The number of the papillæ is varying individually in tbe 
male. De Man indicates 19 for his male; the same number I 
count in the above named male from Varde Aa; on the young 
male, still inclosed in the larval skin is seen 15; on a male from 
Lynæs I count 17; in another, abnormally having the papillæ 
arranged in groups I count 18. This specimen is figured 
(fig. 48). 
As to the front part of the animal I do not find the Danish 
specimens agreeing perfectly with the figure and description of 
de Man; he writes: „Die Kopfregion ist abgesetzt, niedrig, 
scheibenformig“. In the Danish specimens the front end is more 
rounded and the constriction behind the „head u not so strongly 
marked. 
Zeiss O k ularmikrom. A. Oc. 2. 
^ with 7 eggs in the £ without eggs. cT from Lynæs. 
uterus. 
Length 175 = 
Length 247 
Length 126 = 
2,83 mm. 
4,00 mm. 
2,04 mm. 
Oes. 40. 
Yulva 85. 
Tail 10. 
Width 4. 
Tail 16. 
Width 4. 
Vulva 127. 
Oes. 52. 
Oes. 42. 
Tail 2. 
Width 3. 
a = 44 
= 4 1 /2 
« = 62 
/9 = 4V> 
X = 15 1 /* 
