LIFE-HISTORY OF BUCEPHALUS HAIMEANUS. 643 
He hazards the opinion that “In all probability the oyster 
is freed from its intruding guest before the winter sets in.” 
Giard (30, 1874) found in the viscera of Belone vul- 
garis, especially in the liver, genital glands, and _peri- 
toneum, many little cysts which contained untransformed B. 
haimeanus. He thinks it probable that B. haimeanus 
becomes transformed into some species of Gasterostomum in 
the intestine of some large fish which eats Belone, possibly 
the shark. 
Badcock (81, 1875) describes the swimming of B. poly- 
morphus as “flying like eagles through the water with a 
general upwards tendency.” 
Stewart (32, 1875) describes the pavement-like appearance 
of the surface of B. polymorphus. He describes the 
musculature of the body, and thinks that the three-lipped 
invagination at the point of the body is the mouth and the 
complex of glands is the pharynx. 
Ulicny (19) describes B. intermedius from Anodonta 
cellensis, which differs from B. polymorphus chiefly in 
the fact that the median portion of the tail is more deeply 
constricted and lengthened at the sides, “der bisquitformige 
Anschwellung des B. polymorphus” being differentiated 
into two independent bodies. 
Ercolani (22) describes Cercaria bucephalus, which 
differs from B. polymorphus in having a divided intestine 
and the mouth opening in the anterior end. He believes 
that the tails form sporocysts. It is quite possible that he 
has fallen into Pagenstecher’s errors in both instances. 
Levinsen (16) figures the transformation of the germ-balls 
into B. crux, which, in its older stages, is very different in 
appearance from the other forms of Bucephalus which have 
been described. 
Ziegler (7) gives a most accurate account of the structure 
of B. polymorphus and of G. fimbriatum, together with 
an account of the biology of the animal. From the anatomi- 
cal resemblance he concludes B. polymorphus to be a larval 
form of G. fimbriatum. 
