42 THE VOYAGE OF H.M.S. CHALLENGER. 



at night or by accident only. The peculiar organ below the eyes is without doubt of 

 the same nature and has the same function as similar structures on the side of the head 

 of other deep-sea fishes ; as in Pachystomias, it is partly free, as if it could be made to 

 protrude out of the pit in which it lies. 



Kner places this fish in the Berycidse, from which family it is removed by the 

 different structure of its fins. I have not been able to examine specimens. 



Family C Y T T i D ^. 



Cyttus, Gthr. 



The two species of this genus which were previously known — one from Madeira, the 

 other from the coast of South Australia — are large-eyed fishes which probably inhabit 

 the same depth as our John Dory {Zeus), and which on the evidence extant cannot be 

 included in the deep-sea fauna. The small fish, of which we here give a description, 

 is reported to have been taken at 400 fathoms, and diff"ers in some particulars from the 

 diagnosis given for the genus, which differences, however, do not seem to me to call for a 

 generic separation. There is nothing in its organisation which would lead one to suppose 

 a priori that it comes from a greater depth than its congeners. 



Cyttus ahhreviatus (PI. X. fig. B). 



Platystetlms abbreviatus, Hector, Trans. New Zeal. Inst., vol. vii., 1875, p. 247, tab. xi. 



Cijttus abbreviatus, Hector, loc. cit, vol. ix., 1876, p. 4G5. 



Aiitigonia mulleri, KJunzinger, Sitzungsb. Akad. Wien, Ixxx., 1880, p. 380, taf. v. fig. 3. 



B. 6. D. 7/26. A. 2/26. P. 16. V. ^. 



Eesembling the boar-fish in general appearance, the body being much compressed and 

 elevated. The highest point of its upper profile is the root of the first dorsal spine, the 

 greatest depth of the body being more than one-half of the total length, without caudal. 

 The lower profile is also convex, but less so than the upper. The head participates in 

 the general form of the body, and its length is more than two-fifths of the total, without 

 caudal. Peduncle of the tail very slender, much longer than deep. 



The eye lies immediately below the upper profile and is large, at least as long as the 

 snout, and two-fifths of the length of the head. Snout pointed, with the lower jaw 

 projecting and the mouth obliquely directed upwards. The distal portion of the maxillary 

 is dilated, and terminates on its antero-inferior corner in a narrow process, which, when 

 the mouth is half open, projects downwards like a moustache. T"^^ cleft of the mouth 

 does not extend to below the eye; the mouth is very protractile, ^^ posterior inter- 

 maxillary processes sliding in the deeply excavated interorljital space, which is much 



