MYXINIDZ. 341 
interest. It establishes the occurrence of the family nearer the equator and 
at greater depths than before noted, and it differs from the other species 
of the genus in possessing a smaller number of gills. In its dentition it 
approaches Homea, having similar numbers of teeth and the same amounts 
of confluence in their bases as appear in that genus. Of the species of 
Myxine its nearest ally apparently is MM. tridentiger from the Straits of 
Magellan, or, possibly, a Japanese form, secured by the “Challenger” 
expedition, heretofore considered identical. Schlegel’s Heptatrema cirrhatum 
may or may not belong to Myxine; it is rather suggestive of kinship with 
species of Homea from New Zealand or the Cape of Good Hope. 
As regards the general distribution of the family, the presence of Myxine 
has been established in the North Sea and connected waters to the Mediter- 
ranean (J. glutinosa), in the North Atlantic on the western side (JZ. limosa), 
around the southern end of South America (J. australis, M. acutifrons, and 
M. tridentiger), near the equator between the Galapagos and the mainland 
in the eastern Pacific (JZ. circifrons), and in the Japanese seas (the species 
obtained by the “ Challenger”). Vertically the known range in the North 
Sea and about the Straits of Magellan hardly extends more than a 
hundred fathoms from the surface; by the “ Challenger” it was carried 
down to three hundred and forty-five fathoms, off Japan, and by the 
“‘ Blake ” down to five hundred and twenty-four, off the eastern coasts of 
the United States, and by the “ Albatross” still further down to a depth 
of seven hundred and thirty fathoms in the eastern tropical Pacific. In 
general the distribution of the marine Myxinia is sufficiently mdicated in 
the list of species given below. 
The conclusions reached from the study of the material at hand, mainly 
that of the “ Hassler” expedition, belonging to the Museum of Comparative 
Zoology, are of a tenor similar to those obtained from the Discoboli and 
other groups. The Myxinoids are distributed through all the great marine 
basins; they inhabit the deeper waters of the equatorial regions and both 
depths and shoals in the higher latitudes; and the species differ in the 
different localities, similarity of habits and of conditions notwithstanding. 
Though the species taken by the “ Albatross” proves the distribution of 
the genus under the equator, in the absence of representatives from the 
Caribbean it gives no very satisfactory evidence in regard to affinities across 
the isthmus or concerning a former connection between Atlantic and Pacific 
by way of the Caribbean. In fact its testimony weighs rather against the 
