60 
PACIFIC SCIENCE, VoL XIX, January 1965 
tudinally between right cecum and seminal vesi- 
cle, giving rise to a swollen tubular prostatic 
duct well provided with circular muscle fibers 
(pars musculosa). This duct 110-200 X 30-60/x, 
lies transversely along the anterior surface of the 
seminal vesicle and tapering distally opens into 
the base of the cirrus pouch from the ventral 
side. Cirrus pouch subcylindrical, weakly mus- 
cular, 100-175 X 20-2 5ft, containing a narrow 
ejaculatory duct and a narrow muscular prostatic 
duct, the latter two close parallel to each other. 
Cirrus rather short, narrow, unarmed. Genital 
atrium enclosing cirrus pouch, extending but a 
little beyond the point where the uterus opens 
into it. Genital pore opening on a prominent 
marginal papilla projecting immediately postero- 
lateral to left prohaptor at level of eye-spots. 
Ovary subglobular, pre-equatorial, median, 
0.13-0.2 X 0.09-0.14 mm. Shell gland well de- 
veloped between prostatic reservoir and ascend- 
ing vas deferens. Uterus opening into genital 
atrium close to its base. No eggs observed. 
Vagina opening at top of a papilliform pro- 
tuberance on left body margin immediately be- 
hind genital pore; vaginal duct running obliquely 
backward, distinctly muscular for a distance of 
70-80g before leading into retort-shaped recep- 
taculum seminis vaginae, which is 80-100 X 25- 
60g and lies in front of the vitelline reservoir, 
separated dorsally from this by the vas deferens. 
Vitellaria co-extensive with intestinal branches; 
vitelline reservoir anterosinistral to ovary, 40- 
80 X 70-130/x. 
DISCUSSION: The present genus is distin- 
guished from Benedenia Dies., 1858, by pos- 
sessing two pairs, occasionally only one pair, of 
haptoral anchors, and by the structure of the 
male terminalia. It is defined as follows. 
Oligoncobenedenia n. g. 
GENERIC DIAGNOSIS: Capsalidae, Benedenii- 
nae: Prohaptor in form of suctorial saucers, opis- 
thohaptor with scalloped marginal membrane, 
provided usually with two pairs, occasionally one 
pair, of anchors similar to those of Benedenia. 
Pharynx not muscular. Intestinal limbs branched, 
not united posteriorly. Testes entire, juxtaposed 
in midregion of body; Goto’s glands present. Vas 
deferens dilated and turning back on itself just 
before entering base of cirrus pouch. Prostatic 
reservoir with its distal portion differentiated 
into swollen tubular pars musculosa, which pene- 
trates the cirrus pouch at its base. Cirrus pouch 
weakly developed, enclosing a narrow muscular 
prostatic duct and a narrow ejaculatory duct; 
cirrus short, unarmed. Genital atrium extending 
to near base of cirrus pouch, opening on a 
prominent marginal papilla projecting immedi- 
ately posterolateral to left prohaptor. Ovary en- 
tire, median, pretesticular. Vagina opening on 
left body margin Immediately behind genital 
pore; vaginal duct muscular for a short distance 
before leading into receptaculum seminis vagi- 
nae. Vitelline reservoir anterosinistral to ovary. 
Parasitic on marine teleosts. 
TYPE SPECIES: 0 . nasonis n. §p., on gills of 
Naso bexacanthus; Hawaii. 
3. Pseudonitzschia uku n. g., n. sp. 
Fig. 3 
HABITAT: Gill of Aption vires cens (local 
name "uku” ) ; • Hawaii. 
HOLOTYPE: U. S. Nat. Mug.,, Helm. Coll, S.Y. 
No. 3. 
DESCRIPTION (based on 16 whole mounts): 
Body flattened subcylindrical, 2.15-3 .7 mm long, 
with maximum width of 0.5-1. 1 mm at level of 
midregion. Opisthohaptor discoid, attached to 
body proper halfway between anterior margin 
and center of disc, with thickened muscular mar- 
gin distinctly notched midlaterally and incon- 
spicuously at posterolateral margin and flat 
posterior margin. Delicate marginal membrane 
present, but anchors and marginal booklets en- 
tirely absent. Prohaptor glandular, saucer-shaped, 
0.28-0.4 mm long. One pair of eye spots antero- 
dorsal to pharynx. Pharynx 0.08-0.24 X 0.1-0.28 
mm, without lateral constriction. Esophagus 
practically absent. Intestinal limbs with side 
branches, extending to near opisthohaptor with- 
out uniting together. 
Testes rounded, 20-30 in number (most com- 
monly 25-28), arranged in one layer, occupying 
anterior part of postovarian interintestinal field. 
Vas deferens frequently more or less swollen, 
rarely convoluted at very beginning between 
ovary and anterior testes, running forward 
along left margin of vitelline reservoir and then 
thrown into convolutions anterior to this reser- 
