36 
are groups of four and five stalked organs, more or less cup- 
shaped, the surrounding skin deeply pigmented. The function 
of these side organs is probably tactile, or they may serve some 
special purpose at the great depth at which these fish live. 
Analogous organs have been described in the head of the blind 
cave fish. It may be that the side organs are phosphorescent, 
like those of the scopelids. These side organs also recall the 
sense organs of embryo fish. The respiratory apparatus is 
unique among bony fishes. There are air-breathing slits, and 
the water which enters the buccal cavity escapes by a small open- 
ing in front of the rudimentary pectorals. The “ Blake" took 
specimens of this fish in 898 fathoms. It also occurs between 
389 and 1,467 fathoms. 
Of the selachians, few representatives have as yet been 
brought to light by deep-sea explorers, nor is it to be expected 
that such large forms should be captured by the methods 
hitherto employed, although, as has been stated, a regular fish- 
ery for deep-sea sharks (Centrophorus) has existed from time 
immemorial off the coast of Portugal. A species of skate was 
taken by the “ Blake” in 233-333 fathoms. Scyllium and Spi- 
nax also occur below 200 fathoms (Centroscyllium Fabricii 
down to 671). Only three species of selachians at all special- 
ized for deep-sea life have as yet been found, unless perhaps we 
except Chlamydoselachus, thé frilled shark, a representative of 
the devonian selachians, which is found off Japan, where it pro- 
bably is an inhabitant of. deep water. This is one of those in- 
teresting persistent types, like the Australian Ceratodus and the 
American ganoids: the gar-pike and mud-fish. The Japanese 
shark has the teeth of an ancient devonian type, and the em- 
bryonie characters of the lowest orders of recent sharks. 
The lamper eel (Petromyzon marinus) and hag (Myxine 
glutinosa) have both been dredged below 500 fathoms. 
THREE CRUISES OF THE “BLAKE.” 
