424 
Sclerostomes of the Horse 
leaf-crown consists of about forty-eight leaves, an equal number of 
small plates project from their bases into the cavity of the mouth 
capsule and constitute the internal leaf-crown. The mouth capsule is 
a little broader than high, measuring 150-180p in maximum breadth 
and 100-130p in length. The three large teeth have their anterior 
margins denticulated as in T. serratus (Text-fig. 2 A). 
The oesophagus measures 0-97-1-3 mm. in length. A pair of cervical 
papillae are situated at about the level of the excretory opening, 620- 
700 p from the anterior extremity. 
Female : 16-5-18-7 mm. in length. The body attains a maximum 
thickness of 650-750p near the middle, this becomes reduced to 400- 
500p at the level of the base of the oesophagus. The “tail region” 
is elongated but not to quite the same extent as in T. serratus, the 
distance of the vulva being 1-45-1-7 mm., that of the anus 450p from 
the posterior extremity (c/. Text-fig. 3 A). The body has a diameter 
of about 450p at the level of the vulva, behind this point it tapers 
rapidly giving the whole tail region a very pointed appearance when 
viewed under a low magnification (Text-fig. 1 A). The eggs are con¬ 
siderably smaller than those of T. serratus as figured by Looss 1 , they 
measure 90-100p in length and 40-50p in breadth. 
Male : 14 5-15-5 mm. in length, about 650p in thickness near the 
middle of the body and 400-450p at the base of the bursa. The bursa 
has an approximate width of 800p, the median lobe is short and wide 
and is similar to that of T. serratus ; as in the latter species the dermal 
collar of the genital cone covers its anterior face only. The prebursal 
papillae and the rays of the bursa also very closely resemble those of 
T. serratus (Text-fig. 4 A). As in Looss’ species the spicules are very 
thick and provided with relatively small, strongly recurved hooks 
(Text-fig. 6 A); they differ from those of T. serratus in the possession of 
stout barbs projecting backwards from the shafts a short distance 
behind the hooks. The spicules are enclosed in a delicate, finely 
striated sheath. 
T. intermedins was found on several occasions in company with 
other Sclerostomes, both in the colon and caecum. Although many 
specimens were collected it never occurred in sufficient numbers to be 
suspected of causing symptoms of Sclerostomiasis. 
1 In his monograph (1901) Looss omits the. measurements of the eggs; he, however, 
figures those of both species of Triodontophorus in his memoir on Anchylostomum duodenale 
(1911), his figures are x310 which gives a length of about 130 in T. serratus and 97 a 
in T. minor. 
