146 Transactions of the Boyal MiGrosco]pical Society. 
to suppose that B. Haimeanm encysted in Belone vulgaris meta- 
morphoses itself into some species of Gasterostomum in the intestine 
of some big fish which feeds upon the Belone." 
Specimens of Bucejphalus Haimeanus were exhibited to the 
Society by Mr. W. F. Woods, at the Scientific Evening held in 
December, as " living organisms from the cockle." 
EXPLANATION OF PLATE XOVIIL 
Figs. 1 to 5 after Von Baer, 6 and 7 after Lacaze-Duthiers. 
Fig. 1. — Bucephalus polymorphus ; 1 a, n. s. 
„ 2. — „ „ sporocyst, n. s. 
„ 3 & 4. — „ „ different stages of ditto x 20 ; 3 a and h, 
germs from sporocyst, h beginning to 
develop. 
„ 5. — „ „ showing change in lateral appendages. 
„ 6. — „ Haimeanus. 
„ 7. — „ „ sporocyst : a young bud. 
