EEVIEW OF THE SEREANID^. 
429 
longer than the others ; teeth of upper jaw in a broader band, those of the sides not 
in a single series ; teeth all about equal; teeth on vomer in a very narrow, crescent- 
shaped patch ; those on palatines in a band much narrower and shorter than that on 
the vomer. Mouth oblique, the jaws subequal, the lower slightly included. Head 
scaled forward to the anterior nostril ; scales on cheek in about eight series, those on 
opercle about as large as those on body, in'about six series. Profile straight, from 
anterior margin of orbit to tip of occipital crest, rounded in front and behind. Eye 
in snout, 4^ to 5 in head ; interorbital area a little wider than eye. Preorbital 
minutely serrated, the serrre weaker than in P. trucha. Preopercle with minute 
teeth on its vertical border, the teeth near the angle sometimes very much enlarged, 
sometimes little enlarged, more numerous than in P. trucha] serration of the sub- 
opercle and preopercle scarcely visible; opercular spine placed higher than in P. 
trucha, its tip sometimes incompletely two or three parted; a bluntisb projection 
on opercle above the spine. Gill-rakers very short, about equal to one third diameter 
of eye, 6 + 11. Distance of first dorsal spine from snout If to If in length. Height of 
dorsal spines variable, the first always less than half as long as the second, the third 
or fourth dorsal spine highest, 2 to 3 in head, the spines decreasing in height to the 
ninth ; spinous and soft dorsal connected. Caudal truncate when spread out, emar- 
ginate when closed. Anal inserted below the beginning of the soft dorsal, its spines 
graduated, the second thickest; highest ray about half as long as the head; ventral 
If in head; pectoral 1^- to If in head. 
Scales on the body of about equal size, less strongly ctenoid than in P. trticha, 
reduced on breast and head. Lateral line much more strongly curved than in P. 
trucha. 
Color brownish, golden-yellow below, everywhere with brownish dots ; those on 
the lower half of the body scattered with usually a light (blue ?) center, a dusky spot at 
the base of each scale on the sides; all the fins dusky, with reddish brown dots ; 
those on the base of the soft dorsal sometimes aggregated into spots. Head, 3 to 3^ 
in length to base of caudal ; depth 3 to 3+ D. X, 11 or 12 ; A. Ill, 9 or 10. Scales, 10 
or 11-54 to 58-19 or 20. 
This species must be very close to the one called Percichthys melanops, if not 
identical with it. 
Genus XXXIV.— PBRCILIA. 
Percilia Girard, Proc. Ac. Nat. Sci. Phila., 1854, 197 (gillissi). 
Type. — Percilia gillissi. 
Etymology. — Percilia, a diminutive of Perea. 
This genus contains a single species in the rivers of Chili. We know it 
only through imperfect descriptions, and we are not sure that it is really an ally of 
Percichthys. None of the species are in the Museum at Cambridge. 
ANALYSIS OF SPECIES OF PERCILIA. 
a. [First dorsal with nine spines ; snout short and rounded ; maxillary reaching front of eye ; hranchioa- 
tegalsSorG; teeth small, conical; operculum without spines; a few minute spiues along edge 
of preopercle. Color brownish, spotted with black. D. IX-I, 10 ; A. Ill, 8. Lat. l.,35.] (Girard.) 
Gillissi, 124. 
