336 
W. H. DALRYMPLE. 
sub-order, distomata. The principal species of distomes of the 
domestic animals infest the liver, and the hepatic form is, there¬ 
fore, the most important, the first place being taken by the dis¬ 
toma hepaticum 5 the distoma lanceolatum, perhaps, taking a 
secondary position. The former species is pre-eminently a para¬ 
site of ruminants, and, as the name would indicate, is most fre¬ 
quently found in the bile dncts. The lanceolatum is often ob¬ 
served along with the hepaticum in ruminating animals, but it 
has also been observed in the rabbit, hare, pig, ass, dog, cat, and 
man. We have also the distoma texanicum, found in Texas 
cattle, and described by the veterinarian of the Texas Experi¬ 
ment Station, Dr. Francis, a year or two ago. The life-history 
of these parasites is extremely interesting, but time will hardly 
permit of our taking it up at present. 
Coming now to the second class, under the head of entozoa, 
we have the nemathelminths or round worms, which comprise 
two orders. These are the acanthocephali and the mematodes. 
• The former include only the echinorhyncus, which in the adult 
sta^e lives in the digestive canal of vertebrates ; but the latter 
are numerous, and are found in all the organs of the domestic 
animals, with the exception of the bones and the nervous system. 
The following are some of the principal nematodes of the vari¬ 
ous domesticated animals: In the horse, we have the oxyuris 
curvula, found in the caecum and colon. The ascaris megalo- 
cepliala, probably the most common internal parasite of the 
horse. The spiroptera megastoma, found encysted in tumors in 
the walls of the stomach. The strongylus armatus, found in 
the blood-vessels, sometimes in the heart, but chiefly in the 
anterior mesenteric artery. The sclerostoma tetracanthum, 
found in the caecum and colon. The eustrongylus gigas, found 
in the bladder, kidneys, and tissues of the perineal region. The 
filaria lachrymalis, found in the lachrymal duct. And, filaria 
papillosa, found in various locations in the body, and occasion¬ 
ally occupying the anterior chamber of the eye. 
Among the nematodes of the ox, we find the following : The 
ascaris lumbricoides, in the small intestine. The strongylus 
