SIXTY-TWO SPECIES OP FISHES FROM LAKE ERIE 
375 
1-day-old larva . — Length still 5.0 millimeters but yolk sac appreciably reduced. 
5.6 -millimeter stage . — Total length, 5.6; length to vent, 3.0; greatest depth, 0.8; 
diameter of eye, 0.4 millimeter. Myomeres, 15 to vent plus 19 behind (incomplete). 
Characterized by very large pectorals extending past middle of yolk region; large well- 
imbedded eyes; prominent snout; comparatively short intestine; moderate mouth, 
inferior, upper law projecting; dorsal contour very sloping to behind eye; yellow yolk 
sac much reduced with large yellow oil globule in anterior position. 
Pigmentation. — The eye is very dark. About 4 lines of large stellate chromato- 
phores occur on ventral surface of yolk sac, 4 very large subsurface spots over yolk 
region, the last of them immediately before vent, 4 groups (either of a single chromato- 
phore or several) from vent to caudal and a very few on side of head. 
Figure 106 . — Boteosoma nigrum nigrum, 7.1 millimeters 
7 .1 -millimeter stage . — Total length, 7.1; length to vent, 4.0; greatest depth, 1.1; 
diameter of eye, 0.5 millimeter. Myomeres, 15 to vent plus 21 behind. General 
characters as preceding stage, but eye definitely higher, almost at dorsal margin 
with head much depressed above. Embryonic marginal fin low, intact, but slight 
depression above vent and concentration indicating later position of two dorsals and 
anal; ventrals appearing; pectorals very large; caudal lophocercal. 
Pigmentation. — Ventral chromatophores of yolk sac are reduced to a few large 
masses on bottom and sides of stomach region. Four large ones occur on dorsal aspect 
of intestine and six on ventral edge behind vent. Others (subsurface) in this stage 
are evident above each ventral one, and, on the myomeres above the notochord, the 
whole pattern suggests that of a 15-millimeter specimen taken simultaneously. 
