56 
BULLETIN OF THE BUREAU OF FISHERIES 
Specimens 3.8 millimeters long . — The body is deep and compressed, and the tail 
has become proportionately much deeper and less sharply tapering since a length of 
about 2.9 millimeters was attained. The break in the ventral contour described in 
smaller fish remains, but is less pronounced. The greatest depth is now equal to only 
about two-thirds the length of the body to the vent. The mouth, although still 
strongly oblique, has become somewhat lower, the gape anteriorly being only slightly 
above the lower margin of the eye, and the maxillary (which is now well developed) 
reaches a little beyond the middle of eye. The pupil is nearly or quite round, 
as in smaller specimens, and the vent remains situated nearer the tip of the notochord 
than the tip of the snout. The bases of the soft dorsal and anal fins are evident and 
indications of rays are present. The notochord has become curved upward, and below 
it the caudal fin is partly developed with rather definite rays. The pectoral fins are 
short and broad, with indications of rays, and the ventral fins are not evident. The 
color has changed little since a length of 2.9 millimeters was attained. The dark 
markings about the mouth, along the ventral outline of the abdomen, and on the tail 
remain virtually as described in the smaller fish, except that the dark markings on the 
dorsal outline of the tail are a little more prominent and form a somewhat more defi- 
Figure 2.—Menticirrhus americanus. From a specimen 2.9 millimeters long. 
nite stripe. Several indefinite dark markings now are present on middle of side, 
extending from the eye to opposite the vent (fig. 3). 
The principal recognition marks are the same at this size as in 2.9 millimeter 
specimens previously described. The chief changes have taken place in the develop- 
ment of the tail, which has become much deeper posteriorly, the mouth is less strongly 
oblique, and some of the fins are becoming differentiated. 
Specimens about 5.8 millimeters long . — The fish is much more shapely than it was 
when smaller. Yet, the body is quite unlike that of the adult, as it is deep and com- 
pressed. The break in the ventral outline, behind the vent, pronounced in smaller 
fish, is no longer prominent, and the caudal portion of the body has become propor- 
tionately much deeper. The greatest depth of the body is now scarcely equal to two- 
thirds of the preanal length and is contained about 2.75 times in the total length 
to the base of the caudal fin. Myomeres are indistinct anteriorly and again poste- 
riorly, about 25 evident. The mouth remains moderately oblique, and the lower 
jaw is a little shorter than the upper. The gape is wholly below the level of the lower 
margin of the eye and the maxillary reaches nearly opposite the anterior margin of 
the eye. The vent is situated a little nearer the tip of the snout than the end of the 
caudal fin. Considerable advancement in the development of the fins has been made 
since a length of 3.8 millimeters was attained, most of the soft rays being fairly well 
