148 
EXTRACTS FROM FOREIGN PERIODICALS. 
before noticed with sufficient accuracy. On each side of this tubercle are two 
elongated openings, somewhat arched, and crescent.ed: each of these openings 
incloses a tooth ( crochet ) of a light brown colour, the base of which is directed 
towards the tail of the animal. These openings enable the worm to suck, and 
the teeth are to fix themselves more firmly. In fact, every time that I endea¬ 
vored to detach a living individual from the spot to which it adhered, I found 
that the animal’s head was severed before it loosed its hold. 
The head of the male, immediately after its immersion in alcohol, has the 
appearance of a cavity, so that the suction-apparatus is placed upon a hollow 
surface. No distinct separation is observed between the head and the rest of 
the body, because the smooth membrane which covers the head extends, plaited, 
gradually over the whole body. This is again covered by a smooth membrane, 
thin and plaited; but the two sexes differ remarkably with respect to this 
plaiting, more so than as regards that of the anterior parts seen across. 
In the male, indeed, the plaits extend from the head to the end of. the tail, and 
the lateral ridges are neither so distinct nor so well formed as in the female. In 
the latter, on the contrary, the plaits disappear entirely at an inch and one-fourth 
from the caudal extremity, and do not extend over the whole surface of the back 
as in the male. They are only visible at the sides, and vanish altogether in the 
region of the ventral cavity. The lateral ridge itself appears not to be wholly 
uniform in the female, but at the part where the plaits disappeared, the regular 
points which followed immediately after likewise vanish. 
The ventral surface of the male presents a large white band, across the skin; 
it takes its origin near the head, [passes over the middle of the body, and termi¬ 
nates close to the tail. It is there the right testicle, for the left is covered by the 
intestinal canal, which is not seen here, but only at the caudal extremity. On 
the back, immediately behind the head, are two small spots, sometimes visible to 
the naked eye; these are the genital openings, through which the two cirrhi of 
the male probably pass. Behind these two openings are seen two white flexuous 
organs; these are the two testicles, one of which is already seen upon the ventral 
face. Further back is the anal aperture of the intestinal canal, which is situated 
at the end of the tail, and which seems to divide the latter. 
In the ventral region of the female, immediately behind the head, are two 
indistinct blind vessels, which belong to the sexual apparatus, and not, as 
Budolphi conceived, to the intestinal canal. Between these vessels are others 
of a brown colour, describing a sinuous course. They extend nearly to the caudal 
extremity, and constitute the oviducts; they are followed by a simple filament, 
the intestinal canal, which here distinctly divides the tail. 
On the dorsal surface, at the part where the head is slightly arched, are seen 
the tw'o blind vessels before mentioned, and between them an obscure spot, which 
