48 
reaching nearly to the end of the body. The excretory vesicle was 
not seen, but two conspicuous canals run up the sides of the body. 
The testes are oval, 0-52 mm. long. Two thin vasa deferentia run 
up to the vesicula seminalis, which is pear-shaped and very short, 
and enclosed in a short club-shaped cirrus sac, which only curves 
slightly. It reaches behind the ventral sucker for a distance of 
0-3 mm., and encloses a very small pars prostatica and straight 
cirrus ; the male duct opens into the genital sinus in front of the 
ventral sucker. The ovary is globular and separated from the 
anterior testis by a space of about 0-20 mm. From the ovary is 
given off anteriorly an oviduct which runs forward, curving slightly, 
and giving off a long winding Laurer's canal, which is pronouncedly 
swollen at its junction with the oviduct, the swelling looking like 
a receptaculum seminis. It, however, in this specimen contained 
no sperms. Looss states that a receptaculum seminis is absent in 
the genus. The uterus is rather broad, with few openings, and 
runs forward as a vagina, opening by the side of the male duct 
into the genital sinus. The eggs are few in number, and measure 
0-099 mm. bv 0-056 mm. The vitellaria are well developed, and 
reach from the posterior end of the body to the level of the hind 
part of the ventral sucker, running up the sides in two continuous 
bands, not leaving off at the sides of the testes, and filling up the 
space behind them. 
Stephanochasmus baccatus (Nicoll). (Larval form.) 
The encysted form of what is probably the above species, the 
adult of which was found by Nicoll in the Halibut at St. Andrews, 
has been described by Johnstone- under the name of Dtstomum 
valdeinflatum, Stossich, and by myself as the young of 8. baccatusA 
It occurs encysted under the skin of the Dab, Witch, and Long 
Rough Dab very commonly on this coast. 
The life histories of the species of Stephanochasmus are not known 
in any case completely. Several encysted species have been found 
by various workers in fish, so that in all probability a fish is the 
usual intermediate host for the species of this genus. No earlier 
stages have been recorded as far as I know, except a cercana found 
by b my self in the common limpet, Patella vulgata, which was 
described but not named.! It occurred only once in a limpet from 
J SS^a^Noffiuberland Coast, No. II." Trans. Nat. Hist. Soc. North**., 
CtC V^n^S'SuS^ting Trenratodes," by the write, Ann. and Mag. Nat. Hist. 
1907, page 105, plate VIIL, figs, c, d. 
