430 
Sclerostomes of the Horse 
This species is by far the most abundant of the three observed in 
the Birmingham district, it was found on several occasions in enormous 
numbers in the colon and caecum in horses suffering from intestinal and 
other troubles. When alive T. tenuicollis is semi-transparent of a 
whitish colour, tinged with a blood-red pigment; the latter is often 
restricted to the anterior end and in this position is most brilliant, the 
coloured extremity contrasting vividly with the rest of the body. The 
pigment lies partly in the body-cavity and therefore cannot be con¬ 
sidered simply as blood derived from the host 1 . 
Triodontophorus brevieauda sp. n. 
Specific diagnosis. Triodontophorus : the body appears rather 
blunt owing to the somewhat thick extremities. The head is broad 
(270-325p.) and separated from the body by a gentle constriction 
behind the mouth capsule. The mouth-collar is very characteristic, 
being high and erect, attaining its greatest breadth anteriorly so as to 
appear separated from the rest of the head by a deep constriction 
(Text-fig. 2 C). Owing to the large size of the head the elements of the 
leaf-crowns are more numerous than in the preceding species, the 
average number being 60. 
The mouth capsule is large, appearing nearly as long as broad and 
measuring 160-210/x by 200-250p.. The anterior edges of the teeth 
are not denticulated and present a similar appearance to those of 
T. minor Looss (Text-fig. 2 C). The cuticle of the whole body is trans¬ 
versely ringed. 
The oesophagus varies in length from 0-9 to 1-4 mm. The cervical 
papillae are, as in the other species, situated close to the level of the 
excretory pore, 730-880 p from the anterior end. 
Female : 16-17 mm. in length. The body has a thickness of 670- 
700p in the middle and tapers gently towards the anterior extremity, 
the thickness at the level of the oesophageal termination being about 
500p. The shape of the posterior extremity is very characteristic; 
the anus is only 100-130 p from the end and the vulva is immediately 
in front of it (Text-fig. 3 C), the distance between the two openings 
averaging 170p. The body has a breadth of about 420p just in front 
of the vulva and tapers so suddenly behind this point that the whole 
1 Cf . Looss’ remarks on the coloration of Anchylostoma duodenale (1905, p. 32), also 
Boulenger (1915, p. 137). 
