Monogenetic Trematodes, I — Yamaguti 
spines which are arranged in a dorsoventral row. 
Genital pore midventral, prebifurcal, 0.38-0.5 
mm from head end. 
Ovary equatorial, tubular, originating with 
or without enlargement, immediately in front 
of anteriormost testes, describing a double loop, 
with its distal end directed posteromesad, 
measuring 0. 5-0.7 X 0.6-0.9 mm as a whole. 
Genito-intestinal duct short, opening into right 
intestinal limb at level of ootype. Uterus mid- 
ventral; eggs elliptical, about 0.17 X 0.07-0.075 
mm, with long convoluted filament at posterior 
pole and a shorter, nonconvoluted filament at 
opercular pole. Vitellaria commencing at a level 
halfway between intestinal bifurcation and level 
of vaginae, extending along intestinal branches; 
vitelline reservoir Y-shaped, overlapping ovary 
on its ventral side. Vaginae double, dorsolateral, 
symmetrical, opening a short distance behind 
intestinal bifurcation, 1.0-1.25 mm from head 
end; each opening provided densely with acicu- 
lar spines, surrounded by extremely finely den- 
ticulated cuticle, with a conspicuous ventral 
lateral depression immediately in front; at the 
bottom of this pit is a mass of over a dozen 
minute conical teeth representing an accessory 
vaginal armature. This accessory vagina is con- 
nected with the vagina proper by a narrow duct. 
Vaginal ducts running posteromesad, each prob- 
ably joining anterior part of collecting vitelline 
duct of its own side. Longitudinal collecting 
vitelline duct was seen filled with sperm in one 
paratype. 
DISCUSSION: This genus bears a superficial 
resemblance to Monaxine Unnithan, 1957, but 
differs fundamentally in the vagina being paired 
and in having symmetrical, ventrolateral, pre- 
vaginal depressions, each of which is provided 
at the bottom with a small dense mass of conical 
teeth. These two characters are sufficient to 
justify the erection of a new genus, for which 
the name Allomonaxine is proposed. 
Allomonaxine n. g. 
GENERIC DIAGNOSIS: Axinidae, Monaxininae: 
Body relatively large, asymmetrically flattened 
conical. Clamp skeleton of Microcotyle type; 
median spring without apical piece; lateral scle- 
rites unjointed. Esophagus slightly diverticulate; 
intestinal limbs with inner and other branches, 
not united posteriorly. Testes very numerous, oc- 
87 
cupying whole postovarian interintestinal field. 
Vas deferens undulating, but convoluted behind 
intestinal bifurcation. No cirrus differentiated. 
Genital atrium muscular, armed with spines of 
different types; genital pore prebifurcal. Ovary 
in midregion of body, forming a double loop, 
with its distal end directed posteromesad. No 
seminal receptacle. Eggs with filament at each 
pole. Vaginae double, opening dorsolaterally at 
a short distance posterior to intestinal bifurca- 
tion; a prevaginal depression present ventro- 
laterally, with a small dense mass of conical teeth 
at its bottom. Each vaginal duct probably open- 
ing into anterior part of longitudinal collecting 
vitelline duct of its own side. Vitellaria com- 
mencing a little behind intestinal bifurcation; 
vitelline reservoir Y-shaped, overlapping ovary. 
Gill parasites of marine teleosts. 
type SPECIES: A. carangoides n. sp., on Car- 
angoides sp.; Hawaii. 
Four specimens similar in structure but def- 
initely smaller in size, from the gill of Caran- 
goides ferdau gave the following measurements : 
Body 3-4 X 1.3- 1.8 mm with 44-46 clamps; 
anterior sucker 40-60 X 70-100/q pharynx 30- 
40 X 30-38 fx; genital atrium 0.14-0.16 X 0.17- 
0.2 mm, with spines exactly similar in number, 
size and arrangement to those of Allomonaxine 
carangoides. Vagina 0.64-0.8 mm from head end. 
Ovary 0.36-0.48 X 0.36-0.56 mm. Although the 
above measurements are entirely different from 
those of gravid specimens of Allomonaxine 
carangoides, I prefer for the present to regard 
these four specimens as juvenile forms of this 
species. 
16. Pseudochauhanea sphyraenae n. g., n. sp. 
Fig. 17 
HABITAT: Gill of Sphyraena barracuda; Ha- 
waii. 
HOLOTYPE: U. S. Nat. Mus. Helm. Coll., S.Y. 
No. 16. 
DESCRIPTION ( based on five whole mounts ) : 
Body lanceolate, tapered anteriorly from level of 
vagina, usually 4.45-5.8 mm long, but may be 
up to 10 mm long when completely relaxed, 
with maximum breadth of 0.32-1.4 mm at post- 
testicular level. Opisthohaptor without terminal 
anchors, asymmetrical, without attenuated stalk 
as seen in Chauhanea madras ensis Ramalingam, 
1953; clamps unequal, with skeleton of Gastro- 
