THE TRUE FISHES. 173 
Lamp-Fishes (Stomiatide).—In these and allied fishes 
the skin is naked, or the scales extremely minute, and 
nearly all have organs that look like pearl or glass buttons 
imbedded in the skin. According to Leydig, they are of 
three kinds : first, eye-like organs ; second, pearly, glass- 
like organs ; and, third, luminous organs. According to 
different authors, they are eyes, electric or light-giving 
organs. Gunther considers them all luminous, and that 
their function is to light the dark recesses of the submarine 
world. 
In the Stomias the pearly spots are along the ventral surface, a 
veritable row of glowing lights. Allied to the Stomdas is the lamp- 
fish (Scopelus); upon its head is a soft prominence that glows like a 
head-light. Willemoes-Suhm says, “‘One of them hung in the net 
like a shining star.” Other phosphores- 
cent spots are scattered along the lower 
surface of Scopelus Humboldti and Be- 
noitit (Fig. 216). Another allied form 
is the Bombay duck or Harfodon (Fig. 
216), that is luminous over its entire sur- 
face. The eyes of /pmops are adapted 
for receiving and perhaps emitting phos- 
phorescent light, and a curious phos- 
phorescent organ is found upon the head. FG. 215.—Luminous organ 
Several species of the genus Echiostoma from side of Scope/us 
live in Australian seas at a depth of two (Fig. 216, 8). 
and a half miles. They are black, with 
long, fringed barbels, and below the eyes and in other places are 
several luminous spots. The Bathyophis ferox lives at a depth of 
nearly three miles, the greatest depth attained by any fish. It has 
long barbels or feelers, and rows of gleaming lights on its various 
parts, Allied is the Chaudiodus (Fig. 216, 1). The tips of the fins 
are luminous, while a row of luminous spots extends the entire length 
of the body. The little fishes Avgyropelecus (Fig. 217) and Ster- 
noptyx are found in the Mediterranean, The body is extremely deep, 
rising suddenly and narrowing off to the tail. The luminous spots are 
in groups from the head to the tail, Perhaps allied to this group isa 
strange fish (Fig. 218) about twenty inches in length, with a pouch-like 
mouth and no fins, found in water over a mile deep in the Mediter- 
ranean, and also dredged off the American coast. It differs from all 
9 
