BOTHRIOCEPHALUS, a genus of ces toid worms which is found very abundantly in the intestines of predaceous flshes, and one species of which is sometimes found in the in testinal canal of man. It belongs to the same family as the tapeworm (Ta'nia solium), but it is distinguished from it by having its segments broader than they are long; by wanting the four discs which surround the head of the tapeworm, and having in their place two lateral longitudinal openings; and thirdly, by having the sexual organs on one of the flat surfaces of each segment instead of at the edges of the segments. The two longitudinal openings (whence the worm receives its name, from bothrion, a little pit, and kephali, the head) do not seem to be organs of nutrition, but merely a kind of suckers by which the worm is enabled to attach itself to the intestines of the animal which it infests, while it is nourished by ab sorption throughout its whole length. Al
though, as already stated, this worm generally infests the bodies of predaceous fishes, it is capable of being transmitted to all vertebrate animals, and especially it is found in those birds which live upon fish. The only species which is found in the intestines of man is the Bothriocephalus lotus, and it is rare to find even this species except among the inhabitants of two distinct parts of Europe, the north and the centre. It is found, on the one hand, in Russia, in Norway and in Sweden, and on the other hand, in Switzerland, the north of Italy, some provinces in Germany and some depart ments of France, but rarely elsewhere. It has been remarked that this worm is common where the Tnnia or true tapeworm is rare, and vice-versa. It is rare in the United States, but with the increase of emigration from the regions of Europe where it abounds, its occur rence may be looked for.