1702 
Small fishes of the open seas, usually found far from 
shore. They usually live In deep water, moving to the sur¬ 
face at night. Some species are solitary, others social, as 
they have been found in large schools or several hundred 
individuals at one time. Their food is largely Crustacea, 
though they also devour smaller or larval fishes. Lernean 
copepods are also found on some species, though rather infre¬ 
quently. 
Sexual dimorphism occurs with respect to the supracaudal 
and infracaudal luminous bodies or plates, the former with 
respect to the male and the latter the female. Exceptions 
to this condition have been reported, as sometimes they are 
absent and again both supracaudal and infracaudal plates may 
be developed in one individual. 
Many writers use a system of abbreviations or the combin 
ation of certain letters to designate the various photophores 
This is a method often confusing and however laudlble in 
condensing the lette press is surely apinful in application. 
For this reason I have written out all the designations for 
the photophores (see accompanying figure). 
