420 ENTOZOA. 
of the whole number, and lives between the fibres of the mus- 
cles of the Hog, producing the disease called measles. It is 
small, and multiplies prodigiously in this disgusting disease, 
penetrating into the heart, eyes, &c. Similar animals have, it 
appears, been observed in certain Monkeys and even in Man, 
but they are said to be never found in the Wild Boar *. 
The Acrostoma, Le Sauvage, Ann. des Sc. Nat. is closely allied 
to this genus. The animal inhabits the amnios of the Cow. 
Canurvs, Rud. 
Here we find several bodies and heads adhering to the same bladder. 
C. cerebralis; Tania cerebralis, Gm.; Goetz., XX, A, B; 
Encyc., XL, 1—8. This celebrated species is developed in the 
brain of Sheep, destroys a portion of its substance, and pro- 
duces a disease called the Staggers (towrnis), because it compels 
them to turn on that side as if affected with vertigo. ‘The same 
species has been observed in the Ox and other Ruminantia, 
where it produces similar effects. Its bladder is sometimes as 
large as an egg, and its parietes are thin, fibrous, and exhibit 
evident contractions. The little worms are hardly half a line in 
length, and re-enter the bladder by contraction f. 
Scorex, Mull., 
Where the body is round, pointed behind, extremely contractile, 
and terminated before by a sort of variable head, round which are 
two or four suckers, sometimes resembling ears or ligule. Those 
that are known are very small,and inhabit fishest. I have seen a 
large one. 
S. gigas, Cuv.; Gymnorhynchus reptans, Rud., Syn., 129, 
which penetrates into the flesh of the Sparus rai, L. The middle 
of its body is inflated into a bladder, which, during the life of 
the animal, alternately widens and contracts in the middle. 
FAMILY IV. 
CESTOIDEA. 
The fourth family comprises those which are destitute of external 
suckers. 
But one genus is known. 
Liguta, Bloch. 
Of allthe Entozoa, these appear to be the most simply organized. 
Their body resembles a long riband; it is flat, obtuse before, marked 
with a longitudinal stria,and finely striated transversely. No ex- 
ternal organ whatever is perceptible, and internally we find nothing 
but the ova, variously distributed in the length of the parenchyma. 
* For the remaining species, see Rud., Ent., II, p. ii, p. 215, and El., 179. 
+ Here should probably come the genus Ecuinicoccus, Rud., II. p. ii. 247, but 
I have not seen it, and have no idea of it sufficiently clear to enable me to class it. 
t See Rud., Hist., II, p. 3, and Syn., 128. 
