12 Crassicauda 
Measurements made from the complete male and an incomplete female 
were as follows (in millimetres): 
<? $ 
Length of buccal cavity . . . 0*18 0-23 
Length of anterior portion of oesophagus 1-85 1-95 
Thickness of anterior portion of oesophagus 0-11 0-16 
Length of posterior portion of oesophagus about 25-0 about 31-0 
Thickness of posterior portion of oesophagus 0-3—0-4 0-47—0-8 
Distance from anterior end to nerve-ring 0-5 0-4 
(neck of worm 
contracted) 
The genus Crassicauda has hitherto been assigned tentatively to the family 
Filariidae, but the posterior position of the vulva is a character difficult to 
reconcile with this arrangement. It may be remarked that in this feature, 
as well as in the general structure of the oesophagus and buccal cavity, now 
described for the first time, Crassicauda somewhat resembles Tetrameres 
(— Tropidocerca, Tropisurus), a genus usually included in the Spiruridae, but 
placed by itself by some authors in a family Tetrameridae. The globular 
form characteristic of the mature females of Tetrameres is not, however, seen 
in Crassicauda. 
REFERENCES. 
Baylis, H. A. (1910). On Crassicauda crassicauda (Crepl.) [Nematoda] and its Hosts. 
Ann. and May. Nat. Hist. (8), xvn. 144-148. 
- (1920). Observations on the Genus Crassicauda. Ibid. (9), v. 410-419. 
