6 THOMPSON YATES LABORATORIES REPORT 
The parasites inhabit the tracheae and bronchi of birds and mammals, fowl, 
pheasant, turkey, peacock, partridge, magpie, crow, duck, goose, etc. 
Life History : The ova escape from the body with fully formed embryos in 
them, by the decay or rupture of the parent. They hatch in damp earth or water in 
from one to six weeks, and on being swallowed develop into adults which produce 
eggs in less than three weeks. 
Genus Ollulanus. The name is derived from the characteristic appearance of 
the chitinous buccal capsule, which is urn shaped. The male has two short spicules ; 
the female a single ovary. 
One species only is known, O. tricuspis, found in the intestine, bronchi, and 
other parts of the cat. The larvae become encysted in the muscles of the mouse. 
Genus Oesopbagostoma. Small circular mouth has a chitinous ring around 
which the cuticle is raised into a transparent pad on which are six sharp papillae. The 
pad is separated from the body by a constriction behind which the integument forms 
an ovoid swelling well limited posteriorly, at the level of a transverse cleft which 
occupies the whole breadth of the inferior surface. A few species are known which 
inhabit the intestine of the ox, horse, chamois, sheep, etc. 
Life History : The adults are free in the intestine, the larvae live in small 
tumours in the mucous membrane. 
III. Trichotrachelidae 
This family is characterised by the anterior end of the body being long and 
whiplike, the posterior somewhat swollen. The mouth has no papillae ; there is no 
oesophageal bulb. Males may have no spicule, or more often a single spicule sur- 
rounded by a sheath. The females have a single ovary ; the vulva is situated at the 
beginning of the thicker portion. Some are ovoviviparous, others oviparous. Their 
eggs have two characteristic poles. 
Genera : Trichocephalus, Trichosoma, Trichina, and others. 
Genus : Trichocephalus. The anterior and posterior parts well marked. The 
ventral surface shews anterior by a broad longitudinal band formed by a number of 
punctiform projections. The male tail is twisted spirally, with its concavity corres- 
ponding to the dorsal surface. The female has a single ovary. 
Several species are known, inhabiting the intestine of mail (T. dispar), monkeys, 
lemurs, swine, hog, peccary, dog, cat, sheep, deer, ox, etc. 
The life history is simple ; there is no intermediary host. 
Genus : Trichosoma. The posterior part containing the intestine and generative 
organs, is but very little swollen. The posterior end of the male has no papillae, but 
bears a rudiment of a bursa. 
