Genus ScMstorchis — HANSON 
451 
from seminal vesicle to shallow genital sinus. 
Seminal vesicle ovoid^ extending posteriorly 
nearly to ovary, narrowing into nonmuscular 
pars prostatica surrounded by several pro- 
static cells. Cirrus lacking. Ovary rounded, 
0.124 to 0.153 mm. long by 0.146 to 0.153 
mm, wide, lying to right of median line, con- 
tiguous with anterior testis. Short uterus with- 
out lateral coils, with 2 straight, longitudinal 
limbs, one ventral, one dorsal; latter joining 
pars prostatica near genital pore (Fig. 2^), 
intercecal, to left of median line, preovarian 
and well filled with eggs. Mehlis’ gland dorsal 
and to left of ovary, diffuse,- extending from 
level of mid-ovary anteriorly, slightly larger 
than ovary, Laurer’s canal well developed, 
opening dorsal to left cecum at level of sem- 
inal vesicle, directed at first anteriorly than 
at mid-acetabular level turning backward; 
basal portion near ovary swollen. Seminal 
receptacle large, claviform, lying dorsal to 
and slightly anterior to ovary, Vitellaria of 
small follicles often grouped 2 or 3 together, 
extending from level of posterior edge of 
acetabulum to very near posterior end of 
body, lateral and ventral to ceca, somewhat 
confluent posterior to testes. Prominent yolk 
ducts extend from both sides at level of ovary, 
ducts seemingly swollen into reservoirs in one 
specimen. Eggs usually collapsed, 48 to 54 
by 36 to 43 /i (majority 51 to 53 by 36 to 
39 m)- Excretory pore ventral, subterminal, 
slightly anterior to ani and on median line; 
I-shaped vesicle, extending to posterior edge 
of posterior testis, joined there by principal 
pair of collecting tubules; tubules extend 
anteriorly just median to ceca, cross ceca 
ventrally beginning at level of ovary, conti- 
nuing forward to pharyngeal level. 
COMPARISONS: 5. zancli is most similar to 
S. stemsoma of the other known species of the 
genus. S. zancli is like 5. stenosoma and different 
from all other species in the genus in the 
possession of body spines, and in the presence 
of 11 testes arranged in a single, median row. 
It differs from S. stenosoma in that it has a more 
rhomboidal oral sucker, a larger, more rec- 
Fig. 2. Schistorchis zancli from Zanclus cornutus (L.), 
Moorish idol or kihikihi loulu. a. Ventral view; b, ter- 
minal genital ducts (ventral view). Drawn with the aid 
of a camera lucida. Projected scale in millimeters. 
Abbreviations: a = anus, gp = genital pore, gs — 
genital sinus, mg = Mehlis’ gland, pp = pars prosta- 
tica, sr ~ seminal receptacle, sv = seminal vesicle, 
t = testis, ut — uterus. 
tangular pharynx, a greater angle at the origin 
of the ceca, a relatively more posterior ace- 
tabulum, more anterior extent of the vitel- 
laria, fewer and smaller vitelline follicles, a 
more robust body, a preovarian uterus, ellip- 
soidal or ovoid rather than round testes, a 
relatively shorter posttesticular space, a non- 
muscular pars prostatica, a non-bipartite sem- 
inal vesicle, subterminal ani without cuticular 
furls, and a subterminal excretory pore. 
The name zancli refers to Zanclus, the genus 
of the host. 
