84 
PACIFIC SCIENCE, VoL XX, January 1966 
the testes zone, with a proximal right end ex- 
panded into an oval mass representing the proxi- 
mal ovary (Fig. 12). Ova are large in the distal 
part of the ovary. Oviduct arises from the distal 
end of the ovary, proceeds backward parallel to 
the left posterior margin of the ootype and opens 
into the latter at its base by the right side. Uterus 
wide with semicuticularized walls, arises from 
the anterior margin of the ootype, extends for- 
ward median ventrally and opens out by the 
uterine pore situated immediately in front of the 
male genital pore. Egg well formed, spindle- 
shaped, 80 X 3 6 /x, but with anterior filament 
broken, observed in the mid-ovarian zone. 
Vitellaria coextensive with the crura and their 
branches from the level of intestinal bifurcation 
to the proximal level of the isthmus between the 
haptor and body. At this level vitellaria become 
confluent across the median line along with the 
intestinal confluence; vitelline follicles compara- 
tively large, spherical or polygonal, 24-36 fi 
wide, few in number. Median and transverse 
vitelline ducts not observed. 
Ootype median, spindle-shaped, 120 X 80 /*, 
situated between the loops of the ovary and 
covered by slightly elongated cells except for a 
central "white” space, where the various genital 
ducts meet (Fig. 12). Genito-intestinal canal 
arises from this space and opens into the right 
intestinal crus. 
Vagina median dorsal, unarmed, of the same 
.size as the male genital pore and situated In the 
angle of the intestinal bifurcation (Fig. 6). 
Vaginal duct median dorsal, crosses the ovarian 
zone and opens into the central wide space of 
the ootype; seminal receptacle triangular, 40 u 
long, and placed between the proximal ovary 
and ootype close to the testes zone. A short nar- 
row duct from the seminal receptacle opens into 
the ootype close to the entrance of the vaginal 
duct. 
HOST: Pristipoma guoraca Blkr., on the gills. 
LOCALITY: Trivandrum (southwest coast of 
India). One specimen collected 20 August 1955. 
DISCUSSION 
The genus Urocotyle is allied to Chorico - 
Pyle Van Benden and Hesse, 1863, but differs 
markedly in the clamp structure. The platelike 
cuticularization of the median spring and its 
advancement as a cuticularized rim in Urocotyle 
is by far too important a character to be regarded 
as a variation. It Is of definite significance in the 
evolution of the group. Moreover, the presence 
of a peglike spine on this cuticularized plate 
sufficiently warrants according this monogenoi- 
dean a new status. The short Isthmus separating 
or connecting the body with the haptor of Uro- 
cotyle is not observed in any existing species of 
Choricotyle . The number of spines around the 
male genital pore may be of significance only in 
species, but the presence or absence of a definite 
vagina Is of greater significance. In species of 
Choricotyle there is no vagina, while in those 
of Urocotyle a median dorsal unarmed vagina is 
present. In view of these marked differences 
Urocotyle is created as a new genus, with Uro- 
cotyle pristipoma n. sp. as the type species. 
The generic name refers to the haptor with a 
tail, i.e., the lappet. The specific name refers to 
the host. 
Dmsumericola n. gen. 
GENERIC DIAGNOSIS: Choriootylinae, with 
haptor demarcated from body by deep lateral 
constrictions. Clamps with long peduncles, me- 
dian spring of the damp broad and ringlike, 
with long spinous process; anchors and lap- 
pet absent; mouth with a sphincter-like ridge; 
pharynx larger than oral pouches; crura con- 
fluent with a median crus in the haptor; testes 
few, intercrural, post ovarian but not entering 
haptor; male genital pore in the mid-oesophageal 
region, armed with a ring of 10 curved hooks; 
ovary U-shaped; median vitelline duct very large; 
receptaculum seminls present; vagina unarmed, 
median dorsal at the Intestinal bifurcation; 
vaginal duct joins the ootype through the recep- 
taculum seminls; genito-intestinal canal arises 
from receptaculum seminls. Parasitic on dus- 
sumerid fishes. 
genotype: Dmsumericola dmsumeria n. sp. 
Dmsumericola dmsumeria n. sp. 
Figs. 13-16 
Body divisible into an anterior narrow neck, 
a median oval body, and a posterior expanded 
haptor formed of two winglike halves, the hap- 
tor being demarcated from the body by deep 
