MYXINIDxE, 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 M. tridcntiger from the Straits of 

 Magellan, or, possibly, a Japanese form, secured by the " Challenger " 

 expedition, heretofore considered identical. Schlegel's Heptatrema cirrhatnm, 

 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 {M. glutinosa), in the North Atlantic on the western side {M. limosd), 

 around the southern end of South America {M. imsiruUs, M. acuiifrons, and 

 31. tndentiger), near the equator between the Galapagos and the mainland 

 in the eastern Pacific {M. cirdfroiis), 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 indicated 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 



