588 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 
they appear as blotches; sides often with niucli light yellow; axil of 
I)ectorals black. Body oval, compressed, with thick short caudal pe- 
duncle and very short head. Profile moderately dei)ressed above the 
eyes. Spinous dorsal raiiidly rising to the fifth or sixth spine, thence 
gradually descending; spinous dorsal higher than soft part; cheeks 
with scales in 2.^- series. Ilead 3^ ; depth 2. D. IX, 14 ; A. Ill, IG ; Lat. 
1.45. L. G inches. Pacific coast of United States; common; the small- 
est of the family. 
(Cymatogasler minimus Gibbons, Proc. Acad. Nat. Sci. Phila. 1854, 125: Aheona irotv- 
hridgii Girard, U. S. Pac. R. R. Surv. Fish, x, 186, pi. 34, tig. 6-10 : Ditrema minimum 
Giiutber, iv, 249.) 
925. A. acaa'OB’a Jordan & Gilbert. 
Color bluish-black above, becoming lighter on sides and silvery be- 
low. Opercles and lower half of sides punctate with black dots and 
shaded with light orange, the latter more intense on the centres of the 
scales and forming a diffuse lateral band; a broad grayish streak back- 
wards from iiectorals to oi)posite origin of anal, this streak without orange 
tint and with the margins of the scales dark by aggregation of black 
points; young specimens with the bright lateral shade more distinct, 
and rosy instead of orange; fins marked with more or less blackish, the 
anal with some yellowish ; a conspicuous black triangular blotch in the 
axil of the pectoral. Body elongate, with a very long and rather thick 
caudal peduncle. Ilead transversely very convex above, and with a 
blunt snout. Mouth small, oblicpie; maxillary reaching but two-thirds 
the distance to front of orbit. Spinous dorsal with the fifth to the ninth 
spines highest, and about equal to the longest soft ray. Caudal forked 
for nearly half its length. Scales on cheeks in 3 distinct series. Head 
4 ; de])th 2f . D. IX, 17 ; A. Ill, 20 ; Lat. 1. 45. L. 7 inches. Monterey 
Bay. California ; abundant in rock-pools. 
(Jordan & Gilbert, Proc. U. S. Nat. Mus. 1880, 299.) 
312.— MICROinETRUS Gibbons. 
Sparadas. 
{Cymafogasier and Brachgistius Gill: Metrogaster Agassiz.) 
(Gibbons, Proc. Cal. Acad. Nat. Sci. in Daily Placer Times and Transcript, May 30, 
1854: tyjie Cgmatogaster aggregatus Gibbons.) 
Body elliptical, oblong, compressed. Head conic. Mouth small, 
oblique, the lower jaw slightly shorter; li])s thin, the lower with narrow 
frenuin or none; teeth small, conical, rather numerous, in one series. 
Gill-rakers moderate, slender. Scales comparatively large. Dorsal 
