PERISTEDIUM CRUSTOSUM. 113 
by a considerable space below the symphysis; lateral barbel with about 
eight groups of barblets, extending backward of the eye to the pectorals 
or to the end of the suborbital keel. Eye large, prominent, half as long 
as the snout, one third of the length of the head, one and one 
third times the interorbital width. Interorbital space arched longitudi- 
nally, deeply concave transversely with strong ridges at the sides.  Gill- 
rakers slender, sharp, three to five plus twenty-four, several rudimentary, 
longest one third as long as the orbit. Surfaces of the head harsh with 
fine granulations, Above the forward part of the eye on the ridge there 
is a group of two or more small sharp compressed hooked spines; behind 
the orbit the ridge rises in a stronger spine, and behind the latter a lower 
one, behind which there is another still lower. At each side of the occiput 
there is a strongly compressed spine, at the end of the ridge, bearing one to 
two cusps. On the top of the basal half of each rostral process there is an 
erect spine, and behind and inward from the nostrils there is a pair of 
similar ones. Above the angle of the mouth there are others standing on 
the serrated edge of the ridge, which latter expands backward across the 
opercles and supports a prominent angle opposite the forward edge of 
the eye, a more prominent one opposite the hinder part of the orbit 
and another at the end of the gill cover, the last one preceded by a small 
one in the indentation. Opercular spine, strong, sharp; suprascapular 
ridge low, rough. A serrated ridge immediately above the upper jaw is 
divided into two above the articular; a lower ridge starting behind the 
angle of the mouth forms three sections, of which the middle one is small. 
Seales rough, granular, wider than long, with strong compressed hooked 
blade-like spines, nine or ten of those in the second row on the back 
of the tail sending a cusp forward as also backward. The spines make 
four keel-like series the second of which forms a continuation of the 
lower postorbital keel, curving downward behind the head till on the 
level of the opercular spine, and the fourth of which continues the keels 
of the abdominal plates from the pectorals. Lower surface naked in 
advance of the pectorals, covered with large granular laterally ridged 
plates backward. A prominent genital papilla. 
Body red in life, more or less vermilion, throat and abdomen whitish, 
upper half of the dorsal on the larger specimens black. On the young 
specimens from which fig. 2, Plate A, is drawn the rostral processes and 
the outer barbel are much shorter, the former only half as long, the 
8 
