Monogenetic Trematodes, I— Yamaguti 
TYPE SPECIES: P. lepidocybii n. sp., on Lepi- 
docybium flavobmnneum; Hawaii. 
11. Allopseudopisthogyne constricta n. g., n. 
sp. 
Fig. 11 
HABITAT: Gill of Lepidocybium flavobmn- 
neum; Hawaii. 
holotype: U. S. Nat. Mus. Helm. Coll, S.Y. 
No. 11. 
DESCRIPTION (based on 20 whole mounts): 
Body elongate, 7.6-16.5 mm long by 0 8- -1.6 
mm, gently curved in widest testicular region to 
the left, but to the right posterior to region of 
body constriction which usually occurs behind 
the midregion of the body. Opisthohaptor asym- 
metrical, with four larger subsessile clamps on 
pore side and four smaller pedunculate clamps 
on other side. Skeleton of small clamps 90-1 30/a 
wide, consisting of two pairs of symmetrical 
lateral sclerites, a pair of accessory sclerites, a 
pair of basal sclerites and a median spring with 
anchor-shaped tip for longer prong and V-shaped 
winglike apical piece for bifid end of shorter 
fenestrated prong. Skeleton of left larger clamp 
190-2 70/x wide, consisting of two pairs of asym- 
metrical lateral sclerites, a pair of accessory 
sclerites, a pair of basal sclerites, and a median 
spring with anchor-shaped tip for longer prong 
and V-shaped apical piece for bifid end of 
shorter fenestrated prong; the proximal outer 
quadrant of the clamp capsule is a little larger 
than the corresponding inner quadrant, thus 
causing asymmetry of lateral and basal sclerites 
which is, however, not so pronounced as in 
Pseudopisthogyne s in which the two lateral scle- 
rites of the proximal outer quadrant show a 
j gentle sigmoid curve. At the extreme posterior 
i end of the body nearer to the small clamp than 
to the large damp is a conical appendage 0.1- 
0.17 mm long and bearing a pair of hooks close 
to its rounded or truncate apex; this hook is 
! ' 46-54/a long from tip of root to height of curve 
of blade, with a very prominent guard curved 
toward the blade. 
Head rounded at apex, 0.19-0.44 mm wide 
at level of ventral mouth aperture; apical gland 
complex present as in Pseudopisthogyne and 
Pseudopisthogynopsis. Paired oral suckers ellip- 
1 tical, 60-100 X 90-140/a, with a median septum. 
77 
Pharynx small, containing cellular element only, 
60-80 X 40-70/x. Esophagus nearly simple an- 
teriorly but sending posteriorly a number of 
lateral branches at right angles, bifurcating dor- 
sal to vagina. Intestinal limbs with few simple 
or ramified side branches and not accompanied 
by vitellaria in constricted region; in the re- 
gion of the opisthohaptor the side branches are 
markedly reduced and the limbs run parallel to 
each other in the median field, being surrounded 
by vitellaria, and terminate near the base of the 
hook-bearing caudal appendage. 
Testes rounded, 120-185 in number, extend- 
ing in 2-4 longitudinal rows in interintestinal 
field from about middle of anterior third to 
equatorial level far away from ovary and never 
reaching to it in strong contrast with those 
of Pseudopisthogyne and Pseudopisthogynopsis. 
Vas deferens markedly winding between anteri- 
ormost testes and intestinal bifurcation, sur- 
rounded by prostate-like gland cells; in the 
region of the vaginal pore it forms a sigmoid 
muscular canal and leads into the pars prostatica 
a little anterior to the vaginal pore. Pars pro- 
statica undulating, muscular, median, 0.16-0.5 
mm long, surrounded throughout its length by 
numerous prostate cells. Ductus ejaculatorius 
cylindrical, 0.16-0.25 mm long, up to 50/a wide, 
provided with a thick layer of circular muscles, 
usually with its anterior end turned back on 
itself before leading into cirrus. Cirrus simple, 
narrow, unarmed, enclosed in a cylindrical pouch 
of longitudinal muscles 0.11-0.23 mm long by 
25-50/a wide. Genital atrium consisting mainly 
of circular muscle fibers and surrounded by nu- 
merous accompanying cells, enclosing distal por- 
tion of cirrus pouch, cirrus and uterus. Common 
genital pore ventrosubmarginal, 0.38-0.7 mm 
from head end. 
Ovary 0.9-1. 8 X 0.12-0.25 mm, composed of 
branched proximal lobe situated near posterior 
end of body proper, a long, tubular, ascending 
portion, and a winding, looped, distal portion, 
from the rather straight, descending, terminal 
portion of which arises the germiduct. Genito- 
intestinal duct opening into right intestinal limb 
anterior to distal end of ovary. Shell gland com- 
plex just anterior to branched proximal lobe of 
ovary. Uterus midventral except for its terminal 
portion running alongside cirrus pouch. Eggs 
