247 
three quarters of the oesophagus are thin, from the beginuing of 
the last fourth part it increases quickiy. The vulva is placed a 
little before the middle of the body; the ante- and postvaginal part 
stand in the relation as 36 to 57. The tail is conical, pointed and 
its distal third is ventrally hent, forming a right angle with the 
proximal part. The female organ is bifid, the ovaries are relative,ly 
small; the uterus being rather spacious appears to be able to contain 
a considerable number of eggs. The hind part of the body of the 
male is ventrally hent, The number of the papillæ is nineteen, 
tbe hindmost is placed close before the anus, the space between 
the last four is twice the space between the others. The spicules 
are short, thick and provided with two longitudinal lists; the 
proximal end of the former is globular and no accessory pieces are 
seen (fig. 40). 
The movements of the animal are exceedingly sluggish. 
Zeiss Okularmi krom. A. Oc. 2. 
Female: 
Length 372 = 6 mm. 
Oes. 24. 
Vulva 144. 
Tail 10. 
Male: 
Length 287 = 4,6 mm. 
Oes. 22. 
Tail 8. 
Width 3. 
Width 4. 
The formula of de Man 
gives 
I ?■ 
1 C?, 
cl = 93, y9 = 15 1 /2, 
a = 96, fi = 13 , 
y = 37. 
X = 36. 
Dorylaimus stagnalis Dujardin. 
1845. Dujardin, p. 231, T. III. fig. c. 
1865. Bastian, p. 106, PI. IX. fig. 35—37 
1873. Biitschli, p. 27, T. I. fig. 4 a—d. 
1876. — p. 379, T. XXV. fig. 13 a—c. 
1884. De Man, p. 186, T. XXXII. fig. 132. 
1&07. — p. 17, T. II & III. fig. 5. 
As might well be expected this species is widely distributed 
in this country. It is not confined to the larger basins as lakes 
