44 
BULLETIN OF THE BUREAU OF FISHERIES 
b. Head and body rather deep, greatest depth about 4.0 in length to tip of tail (notochord); 
mouth well developed, very strongly oblique, the gape anteriorly well above middle of eye. 
Color plain or with a row of minute dark chromatophores along ventral outline of the tail, 
none in advance of vent, sometimes with one dark chromatophore on middle of side above 
vent, occasionally a few on the head Leiostomus xanthurus 
bb; Head and body more slender, greatest depth about 4.5 in length to tip of tail (notochord) ; 
mouth less perfectly developed, the gape anteriorly at about middle of eye; the imper- 
fectly developed maxillary apparently reaching only slightly past anterior margin of 
eye. Ventral outline of the trunk as well as the tail with distinct, well separated black 
chromatophores, also a few definite ones on the head, none on side of the trunk and tail. 
Cynoscion regalis 
aa. Caudal portion of body proportionately shorter and deeper; distance from snout to vent about 
2.2 to 2.5 times in length to tip of tail (without finfold) ; depth immediately behind vent equal 
to or greater than diameter of eye. 
c. Head and trunk rather short and deep, the greatest depth about 3.1 times in length without 
caudal finfold; preanal distance 2.1 to 2.4 times, and postanal distance without finfold 
1.75 to 1.9 times; depth immediately behind vent about equal to diameter of eye. Ventral 
outline of chest and abdomen with dark markings, with a large prominent spot just in 
advance of vent; anterior half to two-thirds of ventral outline of tail with a close-set series 
of dark dots; base of primitive pectoral pale Cynoscion nebulosus 
cc. Head and trunk very short and deep, the greatest depth about 2.6 times in length without 
caudal finfold; preanal distance 2.25 times; and postanal distance without finfold 1.88 
times in length; depth immediately behind vent notably greater than diameter of eye. 
Caudal portion of body with an almost continuous dark longitudinal line along middle of 
side, and another one on the ventral outline; no prominent dark spot in advance of vent; 
base of primitive pectoral pale Menticirrhus americanus 
ccc. Head and trunk rather short and deep, the greatest depth about 3.1 times in length without 
caudal finfold; preanal distance 2.4 times and postanal distance without finfold 1.6 
times; depth immediately behind vent about equal to diameter of eye. Median line of 
abdomen with a small black spot just before vent, generally with an elongated black 
spot on ventral outline at about midcaudal length, sometimes with several small dark 
spots; inner surface of base of primitive pectoral black Stellifer lanceolatus 
cccc. Head and trunk moderately long and deep, greatest depth 3.1 to 3.4 in length without 
caudal finfold; preanal distance 1.9 to 2.0 times and postanal distance 1.9 to 2.2 times; 
depth immediately behind vent somewhat greater than diameter of eye. Ventral out- 
line of tail general^ with a row of black spots; a black spot at angle of opercle; fresh 
specimens with a black vertical band at shoulder, which generally fades in preserv- 
ative; inside of base of primitive pectoral pale Bairdiella chrysura 
KEY TO SPECIMENS 2.5 TO 3.0 MILLIMETERS LONG 
a. Caudal portion of body long, slender, generally longer (much longer in Cynscion regalis and 
Leiostomus xanthurus) than rest of body; distance from snout to vent about 2.0 to 2.5 times in 
total length (without caudal finfold). 
b. An abrupt and pronounced break present in contour at vent; caudal portion of body very 
slender; depth immediately behind vent less than 1.5 times diameter of eye; distance from 
tip of snout to vent about 2.2 to 2.6 in total length without caudal finfold. 
c. Caudal portion of body moderately slender, depth immediately behind vent about 1.1 
times the diameter of eye; mouth almost vertical; the gape anteriorly near level of 
upper margin of eye; a few dark chromatophores on chest or abdomen; an elongate 
one posterior to hind-gut at its juncture with the tail; a series of widely spaced 
chromatophores along the ventral outline of the tail; no black lateral stripe or spots 
present Leiostomus xanthurus 
cc. Caudal portion of body very slender, depth immediately behind vent about equal to 
diameter of eye; mouth moderately oblique; the gape anteriorly at or below middle 
of eye; ventral outline of chest and abdomen generally with a few chromatophores, 
a prominent one just in advance of vent; ventral outline of tail with well separated 
dark chromatophores, one at about midcaudal length enlarged and usually with 
long radiating lines; no black lateral stripe or spots present ..Cynoscion regalis 
