406 ENTOZOA. 
forms but the third. This part, in the male, is spirally con- 
voluted, and a little penis projects near the tail. It is straighter 
in the female, and simply perforated at the extremity. 
It is one of the most common Worms in the great intestines 
of Man, where, in certain diseases, it becomes prodigiously mul- 
tiplied *. 
Naturalists have distinguished from the preceding the 
Tricuostoma, Rud.—Capi.uaria, Zeder, 
Where the anterior portion of the body is but gradually attenuated +. 
Oxyuris, Rud., 
Where the posterior part of the body is attenuated in the manner 
of a thread. 
O.curvula, Rud?; Geetz., VI,8; Encyc., XXXIII,5. From 
one to three inches in length. It inhabits the caecum of the 
Horse f. 
CucuULLANUS, 
Where the body is round, and most slender posteriorly. The head is 
obtuse and invested with a sort of hood that is frequently striated ; 
the mouth is round. 
They have hitherto been found in Fish only. The most com- 
mon species is that which inhabits the Perch—C. lacustris, Gm.; 
Geetz., IX, A, 3; Encyc. XXXI, 6—and also infests the Pike, 
&c. It is vivaporous, about an inch long, as thick as a thread, 
and of a red colour, owing to the blood with which its intestine 
is usually filled §. 
OpuiosToma, 
The same kind of body as the preceeding, but distinguished by a 
transversely cleft mouth, and consequently furnished with two lips. 
O. cystidicola, Rud.;. Cystidicola, Fischer, Monog. It is 
found in the notatory bladder of certain Fishes ||. 
Ascaris, Lin.{ 
The Ascarides have a round body, attenuated at each extremity, 
and a mouth furnished with three fleshy papilla, between which an 
extremely short tube cccasionally projects. This genus is very nu- 
merous in species, which are found in all kinds of animals. Those 
which have been dissected presented a straight intestinal canal, and 
the females, by far the greater number, exhibited an ovary with two 
branches, several times the length of the body, opening externally by 
a single oviduct, near the anterior fourth of the total length of the 
animal. ‘Tiie males hive but a single seminal vesse), also much 
* For the Tricocephali of animals, see Rud., Ent., II, 86, and Syn., p. 16. 
+ See Rud., Syn., 13. 
t Add. Ox. alata and Ox, ambiyua, Rud., Syn., i9. 
§ For the other species, see Rud., Hist., II, 102, and Syn., 19. 
|| Rud., Hist., II, 117. and Synop., 60. 
¥ ’Ackapis, the name of the small species that is found in Man, is derived from 
ackapitw, to leap, to move. 
