16 
BULLETIN OF THE BUREAU OF FISHERIES. 
yellow in color, spotted with dark brown. On the ventral surface the spots cover 
the whole of the basal portion and extend forward in two long points on either side. 
There is also a narrow band of spots across the base of the lower lip. On the dorsal 
surface the spots cover the basal portion behind the eyes, and there is a large patch 
behind and inside of each antenna (fig. 8) . 
The eyes (e) are six in number on either side and are situated outside the bases 
of the antennae and behind the mandibles. Each group of six is arranged in two 
transverse rows, somewhat concave toward each other like parenthesis marks. 
The interval between the two outside eyes is longer both longitudinally and trans- 
versely than between the two inside ones. Each eye is elliptical in outline, the 
long axes of the ellipses in the two rows inclined toward each other. The chitin 
integument over each eye is transparent, and beneath it can be seen the retinal 
pigment, which is uniformly black. In larvae taken from the pupal chamber this 
Fig. 12.— Ventral view 
of left maxilla. 
black pigment entirely disappears, the eyes being apparently withdrawn prepara- 
tory to forming the compound eyes of the adult. 
The antennae {an, figs. 8 and 9) project from the dorsal surface of the head be- 
hind the inner corners of the bases of the mandibles. Each consists of a basal 
joint and three ter min al joints, the former twice as long as the three latter combined 
and three times their diameter. The basal joint carries a fringe of long hairs along 
its inner margin and much smaller and widely scattered hairs over its entire surface. 
The three terminal joints are destitute of setse and hairs (fig. 10). 
MOUTH PARTS. 
The mandibles {md, figs. 8 and 9) are not alike ; the right one is always longer and 
more slender than the left, and the tooth on its inner margin is very much larger 
and bifid at the tip (fig. 11). Indeed, the tooth on the left mandible is hardly more 
than a small spine on the inner margin, and even that is sometimes wanting. The 
