DEVELOPMENT AND LIFE HISTORY OF SOME TELEOSTS 
637 
been made, a few survived much longer and those specimens furnish the clue to the 
further development of the larvae. 
Larvae 7 days old . — The fish shown in figure 154 is 7 days old and was 3.0 mm long. 
This fish differs little from the 4-day old one, already described. Very definite dark 
chromatophores are now present on the head and abdomen, and rather definite cross 
bars generally are present. Anteriorly the body has increased considerably in depth. 
Larvae 14 days old . — Figure 155 is based on a preserved specimen 14 days old, 
measuring only 2.0 mm in length after preservation. It may be assumed that consider- 
able shrinkage had taken place. The fish at this stage is deep and strongly compressed. 
The pigment spots on the dorsal finfold, tending to form bars on the body, are present 
Figure 165. — Achirus fanciatiLS. From a young fish 14 days old. 
about as in the early larvae. The pigment on the ventral finfold, however, is not 
concentrated in blotches in the single specimen studied. A great increase in dark dots 
on the body has taken place. 
Young fish 17 days old . — It is evident from figure 156, based on a specimen 17 
days old, 3.8 mm long after preservation, that development progressed rapidly. The 
fish has become much more shapely. The distal part of the tail, instead of being 
curved downward, is now bent upward, giving it the heterocercal appearance character- 
istic at this stage of development of telosts with homocercal tails. Indications of rays 
are present in the finfolds. Note that the pectoral finfold remains prominent. The 
eyes are quite symmetrically placed on the opposite sides of the head, and there is as 
