THE LAMPREYS 59 
as in Fig. 72, A, and then drawn in by stout tongue 
muscles, 7 (Fig. 69) ; its digestive tube is almost straight, 
terminating at the base of the tail region at A; the 
region of the gullet, OZ, is pierced by a number of 
branchial openings, varying from seven to fifteen, often 
assymmetrical. The body cavity is an extremely large 
one for the size of the contained viscera. An unpaired 
fin, supported by delicate, unbranched (dermal) rays is 
restricted to the hindmost part of the body. Passing 
down the side is a row of mucous pouches by which a 
‘remarkable supply of slime is secreted. The living animal 
is enabled, by the peculiar character of this slimy secre- 
tion, to render a pailful of water jelly-like in consistency. 
Bdellostoma occurs plentifully in the bays of the Pacific 
coast of America, notably at Monterey, California. It is 
active in its movements, is carnivorous, and is well known 
to take a baited hook. Its numbers make it an enemy of 
the fishermen, entangling and sliming their set lines, and 
destroying the captured fish. It is said to feed at night, 
although little is yet known of its general habits of living. 
None but adult specimens have thus far been observed. 
The Hagfish, Wyxine glutinosa (Fig. 71, and 72, 8), is in 
many regards similar to Bdellostoma; it differs mainly in 
the character of its unpaired fin and in its branchial struct- 
ures (Figs. 9, 10). As already noted, the outer ducts of the 
gills, instead of opening separately at the surface as in 
Fig. 70, are drawn together tail-ward, and terminate on 
either side in a common ventral opening (Fig. 71, at the 
point*). The unpaired fin is almost lacking in supports ; 
its ventral origin is even as far forward as the branchial 
openings; the anus, as a slit-like opening, pierces it in 
the tail region. Asin Bdellostoma, the nasal canal begins 
at the snout, and at its hinder opening pierces the roof of 
