New Monogenetic Trematodes, II — Yamaguti 
425 
Lagenivaginopseudobenedenia n. g. 
generic diagnosis: Capsalidae, Benedenii- 
nae. Prohaptors consisting of paired glandular 
saucers placed close together. Opisthohaptor 
discoid, aseptate, with scalloped marginal mem- 
brane, armed with three pairs of anchors. Eye- 
spots present. Head and neck region much nar- 
rower than trunk and well marked off from it. 
Pharynx spherical, without constriction, rather 
glandular, papillate internally. Intestinal limbs 
with dendritic outer branches, not confluent 
posteriorly. Testes juxtaposed, entire. Vas def- 
erens strongly convoluted in front of left trans- 
verse vitelline duct, passing transversely behind 
cirrus pouch and penetrating it near its base. 
Cirrus pouch cylindrical, extending transversely 
behind pharynx, containing small prostatic res- 
ervoir and well developed pars muscularis of 
prostatic duct at its base. Cirrus elongate coni- 
cal, pointed, projecting into thin-walled genital 
atrium. Common genital pore ventrosubmedian, 
well apart from body margin. Ovary entire, not 
separated from testes by vitellaria. Vitellaria co- 
extensive with intestine; no definite vitelline 
reservoir. Vagina lageniform, between uterus 
and right intestinal limb, opening almost mid- 
ventrally behind cirrus pouch; seminal recepta- 
cle well developed. Gill parasites of marine 
teleosts. 
type species: L. etelis n. sp., on Etelis car- 
bunculus ; Hawaii. 
4. Metopisthogyne sphyraenae n. gen., n. sp. 
Fig. 4 
habitat: Gills of Sphyraenu helleri (local 
name "kawalea”) ; Hawaii. 
holotype: U. S. Nat. Mus. Helm. Coll., 
5. Y. No. 48. 
description (based on five whole mounts) : 
Body 4. 4-8. 9 mm long, slender, gradually 
widened toward opisthohaptor which is 0. 8-2.0 
mm long by 0. 6-1.0 mm wide at base and bears 
four pairs of short-stalked clamps and a short, 
trapezoidal, median, caudal lappet provided 
with three pairs of hooks. Clamp skeleton 
0.24-0.3 mm in transverse diameter, consisting 
of a very stout median spring, a pair of inner 
basal sclerites, two pairs of arcuate lateral scle- 
rites and a pair of accessory sclerites ; one prong 
of median spring with three or four minute 
holes, enlarged at apex in form of a triangle; 
other prong* with anchor-shaped apex, may be 
bulbously swollen near its base. Of the caudal 
hooks the larger outermost is 4l-46p long from 
tip of root to height of curve of blade, and has 
a curved guard a little shorter than root; the 
smallest middle is l6-18p long and has a com- 
paratively long root and a short curved blade; 
the innermost is somewhat similar in shape to 
the outermost and 25-28p long. Head rounded 
in front, 0.16-0.32 mm wide, with ventral 
mouth aperture and a pair of groups of gland 
ducts at apex ; paired oral suckers aseptate, mus- 
cular, 70-93 X 58—72|i, close together, fol- 
lowed by ovoid nonmuscular pharynx 51-70p 
long by 48-58[i wide; esophagus 1. 0-2.0 mm 
long, simple, wide, bifurcating just in front of 
vaginal pore; intestinal limbs with short side 
branches, terminating separately, one at base of 
opisthohaptor and the other a little more pos- 
teriorly. 
Testes small, ovoid, 93-162 in total number, 
extending in interintestinal field from anterior 
part of middle third of body to anterior half of 
caudal third, mostly preovarian, partly para- 
and postovarian. Vas deferens strongly winding 
in median field between testes and vagina; in 
the region between the vagina and the pars 
muscularis there are numerous prostate cells, 
though the pars prostatica is not distinctly dif- 
ferentiated. Pars muscularis representing ejacu- 
latory duct, 0.35-0.45 mm long by 4 0-6 Op 
wide, provided with strong transverse or spiral 
muscle fibers, followed by muscular cirrus 0.18- 
0.26 mm long which is bulbously swollen near 
its distal end and projects into the nonmuscular 
genital atrium in the type. Genital atrium open- 
ing on left margin of body at a distance of 
0.55-0.8 mm from head end. 
Ovary tubular, long, folded back on itself 
just medial to left intestinal limb, 0. 3-0.4 mm 
long lineally as a whole, arising about one-third 
of body length from posterior extremity. Ger- 
miduct giving rise to genito-intestinal duct be- 
fore joining vitelline reservoir. This duct opens 
into the left intestinal limb a little anterior to 
the distal end of the ovary. Uterus midventral, 
containing only one fusiform egg in the type. 
Eggs 0.17-0.18 mm long, with rigid bipolar 
filaments 0.15-0.21 mm long. Vitellaria largely 
