CENTRISTHMUS SIGNIFER. 4g 
the snout, more than one fourth of the length of the head. Preopercle with 
numerous fine and regular serrations on the hinder edge, with larger and 
more irregular ones on the lower edge, and with a large sharp compressed 
spine on the angle. Opercle with three flat spines, median stronger and 
nearer the lower, which is very weak. Margin of gill cover thin, concave 
on the edge both above and below the median opercular spine. Urohyal 
very long, as long as the snout and the eye together, upper portion thin, 
ending in a sharp retrorse angle; lower portion less compressed, hinder ex- 
tremity a long sharp point, in front of which there is a groove on the lower 
edge, middle with a strong antrorse spine. By great length in the urohyal 
necessity of much forward extent in the shoulder girdle is obviated; in the 
present species the halves of the girdle are more nearly erect and straight. 
Gills four; rakers short, longest more than half as long as the eye, slender, 
nine plus twenty-four; membranes hardly united, free from the isthmus; 
suprabranchial gland of moderate size, bent forward in its upper half. 
Pseudobranchize well developed. 
Origin of the dorsal above the upper angle of the gill opening; third spine 
very long, with its pennant as long as the head, other spines hardly as long 
as the snout; longest soft rays twice as long as the spinous. Anal medium, 
third spine longest, first spine below the first soft ray of the dorsal. Caudal 
three fourths of the length of the head, lobes sharp, notch deep and rounded. 
Pectorals smaller than the ventrals, pointed. Ventrals one third longer than 
the pectorals, reaching the spinous rays of the anal. inserted below the 
bases of the pectorals, third and fourth rays forming a very long point. 
Scales small, ctenoid, covering body, cheeks and interorbital space, and to 
some extent the bases of the caudal fin and of the paired fins, absent from 
the bases of the dorsal and of the anal and from the maxillaries and the 
lower jaws, as also from a short transverse area behind the interorbital 
region. Lateral line complete, nearly straight to a point below the seventh 
dorsal ray, from which it is distant about seven scales, thence it continues 
nearly parallel with the vertebral outline to the base of the tail. Three large 
pyloric appendages. Air bladder of moderate size. 
Color probably red in life, darker on the back with faint freckles of 
brown, with short streaks or spots of brownish on the crown, with cheeks 
and lower portions of head and body silver. In cases the scaleless area 
back of the crown is darker, and a darker shade in the middle of each scale 
gives the sides a streaked appearance. 
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