144 DEEP SEA FISHES. 
Such depths to the northward as have been dragged with more thorough- 
ness appear to have swarmed with Brotuloids. The definitely ascertained 
distribution of the group includes the Atlantic in the entire northern 
portion and southward off the coasts of Brazil to the Straits of Magellan, 
the Pacific in the Panamic region both sides of the northern portion and 
the southwestern part, off Australia, and New Guinea, and the northern 
extensions of the Indian Ocean. In the vertical ranges the greatest depths 
yet obtained lie in’ the northern Atlantic at 2500 fathoms where the 
species Mizxonus lateralis Giint., and Bassozetus tenia Giint., were taken by 
the “Challenger,” and Aleweferion Parfuiti Vaill., at 2756 fathoms by the 
“Talisman.” The “Challenger’s” greatest depth for these fishes in the 
Pacific was that of Zyphlonus nasus Giint., northeast of Australia at 2440 
fathoms. The greatest depths recorded by the “ Investigator” were those 
of Neobythites pterotus Alc., and Dermatorus melunocephalus Alc., in the Bay 
of Bengal at 1748 fathoms. In the present material of the “ Albatross ”’ 
from the Galapagos section the deepest bottom appears in the case of 
Floleomycteronus digittatus, a new species of a new genus, at 2252 fathoms. 
There is reason to believe some of the young Brotuloids begin life nearer 
the surface. ° 
Habitually the Brotuloids rest on the mud of the sea bottom, like the Lyco- 
doids and as also in the cases of the latter, this habit has led to obsolescence 
of the ventrals until the usefulness of these fins as means of progression is 
completely at an end and they remain in many instances only as compara- 
tively insignificant organs of touch. As seen in the group the various modi- 
fications of the ventral fin range from the two distinct filamentary rays to 
the two rays bound together, the single bifid ray, the single simple filament, 
and the entirely obsolete. Aside from these Holcomycteronus possesses vent- 
rals each of which is composed of two separated rays, the distal ends of 
which are so expanded that they resemble small oars. In the pectorals 
likewise a variety of modification has obtained. Useful in balancing and in 
making quick rushes ahead or back, in all cases these fins are at least moder- 
ately developed. Though the fin is of the normal shape in the greater num- 
ber of the genera, it takes on peculiar forms in others; thus on Nematonus, 
Mixonus, Dicrolene, and Pteroidonus from one to ten of the lower rays are 
separate elongate and enlarged as if for tactile purposes, on Sciadonus the 
carpalia are elongate and the fin is placed at the end of an arm, and on 
Eretmichthys the lower half of the fin is much enlarged, lengthened, and 
