/ 
H. Kobayasiii 397 
of the body and forming a large loop. Vitellaria consist of several long branches, 
which are again subdivided. Laurer’s canal present; receptaculum seminis 
absent. Uterus very long, forming several convolutions between the two 
intestinal caeca. Eggs fairly large, numerous. Habitat: in the air-bladder of 
fishes. 
Type species: L. eurytremum n. sj). 
Leptolecithum eurytremum n. sp. 
Diagnosis . Size of mature distome 13 mm. x 7 mm. Both suckers large, 
the ventral sucker being the larger of the two. Intestinal caeca make about 
five lateral bends. Stem of the excretory vesicle a broad canal at its posterior 
part, but at the level of the shell-glands it narrows abruptly and forms lateral 
bends between the intestinal caeca; at the middle of body it bifurcates, both 
arms make similar bends and finally end near the pharynx. Margin of testes 
entire. \ itellaria consist of about four to five large branches, which divide 
several times. Ovary a long tube about 2*3 mm. in length, lying transversely 
and often contorted. Uterus occupies the space between the intestinal caeca 
and makes about three large transverse bends, each of which has fine undula¬ 
tions. Cirrus-pouch (?) a large ellipsoidal muscular mass, slightly protruding 
in the depression between the pharynx and the ventral sucker. Eggs 0048- 
0*05 mm. x 0-023—0*025 mm. Habitat: in the air-bladder of Parasilurus 
asotus and other fish. 
Description. The mature specimens of this species are found in the air- 
bladder of Parasilurus asotus and Pseudobagrus auranticus, more commonly 
in the former. Several specimens ordinarily occur in one host. In the coelom 
of the above two species of fish and Hypomesus olidus and Richardsonius 
haJcuensis, immature specimens are found. These immature specimens are 
commonly found near the anterior part of the coelom or in the vicinitv of 
the anus. The parasite has been collected from various places in the Okayama 
Prefecture, Sahara (Chiba Prefecture), Kasumiga-ura (lbaraki Prefecture) 
and Lake Biwa. 
A mature specimen measures 13 mm. long and 7 mm. wide at the broadest 
part. The body is compressed dorso-ventrally, broadest at the middle or the 
posterior third of the body, and tapering anteriorly and posteriorly. It has 
on the whole a leaf-like shape. The ventral surface is often slightly concave. 
In the fresh state, it appears flesh pink, showing blackish colour, due to the 
intestinal contents, along the intestine. The living parasites move on slowly 
by the contraction and elongation of the body. 
The cuticle is smooth and measures 0-04 mm. in thickness. The oral sucker 
has a diameter of 1-2 mm. and is situated on the antero-ventral end. The 
ventral sucker is slightly larger than the oral, being 1-4 mm. in diameter and 
is situated at the anterior third. The pharynx is directly continuous with the 
oral sucker and has an elongate form, the size being 0-85 mm. x 0-5 mm. In 
the entire preparation the oesophagus cannot be detected, but in sections a 
26—2 
