LYCHNOPOLES ARGENTEOLUS. 245 
as wide as the interorbital space. Mouth large, oblique, about three fourths 
as long as the head, midlength below the eye ; maxillary short, curved on 
the lower edge, rounded at the end, extending one diameter of the eye 
backward of the latter; intermaxillaries forming more than half the length 
of the upper jaws. Teeth small, unequal, slender, sharp, hooked, in two 
series, alternating, on intermaxillaries and dentaries, in a single series on 
maxillaries and palatines. Six teeth on each palatine. None of the teeth 
are large enough to be called fangs; the inner are opposed to the spaces 
between the outer on each jaw; the maxillary teeth are somewhat inclined 
forward. Gills four; no pseudobranchiz ; gill rakers slender, as long as 
the eye; six plus fourteen on the outer edge of the first arch. Opercles 
very thin. Scales large, broad, thin, deciduous ; cheek scales moderately 
large, very thin, the large one on the maxillary as long as the eye and half 
as wide. Vent midway from the snout to the end of the caudal, below the 
fourth ray of the dorsal fin. Seven pyloric cca, <A short, sharp, spine- 
like angle below the isthmus. 
Dorsal origin midway from the eye to the base of the caudal; base of 
dorsal ending above the eleventh ray of the anal. Anal origin below the 
sixth ray of the dorsal; anal base twice the length of that of the dorsal. 
Ventrals small, half way from the pectorals to the vent. Pectorals small, 
low upon the sides. No adipose fin apparent. Caudal forked. 
The luminous facets are mostly in function downward. With one 
exception, perhaps, each facet is composed of a black substructure on which 
rests a yellow disk, usually at the upper edge in the organs of the sides, 
having toward the lower edge a bluish or silvery area similar in a measure 
to that in the facets of Argyropelecus. In the ventral series of facets on 
each side of the body there is a single one below the snout, followed by 
nine below the hyoid and these by fifteen from the pectorals to the ventrals, 
plus nine from the ventrals to the vent, plus twenty-two from the vent to 
the caudal. In the next series above the ventral there are two facets on 
the operculum plus eleven from the shoulder to the ventrals, plus ten 
from the ventrals to the vent, plus twenty-two from the ventrals to the 
caudal. On the flank above the lower two rows there isa third series of 
smaller facets and above this a fourth of hardly more than dots. The large 
facet between the eye and the intermaxillary is peculiar in that it is hard 
and black at the surface while the yellow matter usually forming the disk 
lies under or behind it as if the facet was in function inward or backward. 
