180 
depressed. The depth of the trunk diminishes but little back- 
wards, and is contained thirteen and a half times in the total 
length without caudal; the length of the head is one-sixth 
of the total. Head broad, much broader than deep, its greatest 
depth being two-thirds of its length. Snout broad, much depres- 
sed, with obtusely rounded anterior profile; cleft of the mouth 
very wide, the maxillary moderately dilated behind and exten- 
Fig. 70. /pnops murrayi Gthr. Head from above and below (after Giinther). 
ding beyond the middle of the length of the head. Mandible 
projecting beyond the upper jaw, broad, but owing to the 
depressed form of the snout its outer surface is nearly entirely 
at the lower side of the snout. Infraorbital chain of bones 
very narrow, wedged in between the transparent lamina and 
the maxillary, with four very distinct apertures leading into 
the mucous duct. The upper surface of the head, including 
the snout, is wholly covered by the two cornea-like laminae 
of the luminous apparatus. They are closely attached to each 
other along the median line, each being divided by a shallow 
transverse ridge into a larger anterior and a smaller posterior 
portion. The ridge turns forward near and parallel to, the 
median line, and marks the course of a superficial mucous 
duct. The gill-laminae are well developed and the gillrakers 
long, needle-shaped, closely set, about twenty-two in number 
on the outer branchial arch. 
The vent is nearly twice as distant from the root of the 
caudal fin as from the end of the snout, and rather more 
than the length of the head from the gill-opening; it is placed 
between the ventral fins. The dorsal fin commences immedia- 
tely behind the vertical from the vent; it is short, but its 
longest rays are twice as high as the body. Origin of the 
anal midway between the vent and the root of the caudal, 
