42 
more attenuate anteriorly than posteriorly, ventral surface flat, dorsal surface slightly 
convex, margins very thin. Oral sucker ventro-subterminal, small, 0.5 mm. in diam- 
eter, 0.33 mm. deep. Ventral acetabulum 1.6 to 2 mm. in diameter, but elongated 
caudally directly under the ventral surface in a 2 to 8 mm. 
long sack; center of acetabulum 1.8 to 2 mm. from anterior 
end of body. Skin without spines. Prepharynx 0.28 mm. 
long; i^harynx 0.7 mm.; esophagus very short so that the 
l)ifurcation of the intestine occurs about on anterior plane 
of acetabulum ; ceca with two characteristic curves toward 
median line, one at equator, the other between the testicles. 
Male organs. — Cirrus pouch cylindrical, median, nearly one- 
fourth as long as the body, 0.25 to 0.33 mm. thick, straight, 
extending from genital pore to about midway to shell gland 
( equator) ; it contains a long sinuous vesicula seminalis with 
a longl)lind sack possessing lateral branches, this sack reach- 
ing from a short distance caudad of acetabulum to about 0.5 
mm. from caudal end of pouch; pars prostatica 0.5 mm. 
long, ductus ejaculatorius rather short, provided with fine 
spines; vasa defferentia near median line; testicles one 
jjosterior of the other; branches of posterior testicle extend 
to within about 3 mm. of the caudal end of the body. Female 
organs: Vitelline reservoir rather small; shell gland 1 to 1.5 
mm. in diameter. Fggs numerous, 120 to 130 j.i long by 77 
to 80 j-i broad. Sporocyst, redia, cercaria, and intermediate 
host undetermined. 
Habitat. — Small intestine of man {Homo sapiens); Asia. 
This parasite has Iteen reported several times 
for man, all the cases being of Asiatic origin, 
eludging from the writings of Dobson (1893a, 
1893b) and Giles (1892, 1893) this parasite is 
probabl}" more common, especially in India, than 
is generally supposed. 
Rathouis’s Intestinal Fluke — FASCIOLOPSIS RAT- 
HOUISI « (Poirier, 1887) Ward, 1903. 
[Fig. 67.] 
Specific diagnosis. — -Fasciolopsis: 25 mm. long, 16 mm. 
broad; whitish, tinted with brown on the margins; oblong 
oval, obtuse, anterior end appears to be provided with a 
more or less distinct short cephalic cone, 3 to 5 mm. broad. 
Oral sucker (?) subterminal, very small, its opening not 
over 0.5 mm. in diameter (after Moniez), or 1.5 mm. (after 
Braun). Ventral acetabulum much larger, situated about 
portion of the cirrus pouch 
which lies caudally of the 
acetabulum: ac., acetabu- 
lum; c. V. s., cul-de-sac of 
the vesicula seminalis; v. 
d., vas deferens; v. s., vesic- 
ula seminalis. (After Odh- 
ner, 1902, fig. 3.) 
2 mm. from the oral sucker, its circular orifice 2 mm. in 
diameter. Skin without spines. Prepharynx (?) ; pharynx 
(?) ; esophagus (?); intestinal ceca (?). 3/ale organs: Cirrus 
pouch (?) (apparently long); vasa deferentia apparently 
rather divergent; testicles side by side. Female organs: Ovary caudad of transverse 
Synonyms. — Distomum rathonisi Poirier, 1^87; Dlstoma rathonisii Huber, 1894 
(misprint); Fasciolopsis rathouisi (Poirier) Ward, 1903. 
