Vorhies—Larva of Platyphylax Designatus. 117 
he (Betten) noted ony six abdominal ganglia, or a total of 
eleven, in the larva of Molanna cAnerea. The supra- and sub- 
oesophageal ganglia show nothing worthy of particular note. 
The three thoracic ganglia occupy the pro-, meso-, and meta¬ 
thorax, the third lying slightly anterior to the middle of the 
metathorax. The first abdominal ganglion, smaller than the 
third thoracic, lies quite close to it posteriorly, within the meta- 
thorax. The second abdominal ganglion, slightly smaller and 
more elongated than the first, lies near the middle of the first 
abdominal segment. The third ganglion, about the size of the 
first, lies at the juncture of the second and third segments, and 
is the only ganglion found in these two segments. The fourth, 
fifth, and sixth ganglia lie in their respective segments, but the 
seventh lies just within the posterior border of the sixth seg¬ 
ment and the eighth, closely applied to it posteriorly, lies just 
within the anterior border of the seventh segment. Although 
the last two ganglia are closely applied to each other they are 
entirely separate, as may be readily seen when stained and ex¬ 
amined microscopically. This arrangement of ganglia will be 
seen at once to offer a possible explanation of Betten’s failure 
to find more than six abdominal ganglia, because, in serial sec¬ 
tions, only six abdominal segments would probably be noted to 
contain ganglia. These would be the first, either the second 
or third, but not both, and the fourth, fifth, sixth and seventh. 
In the two cases where two ganglia are rather closely applied to 
each other, very careful observation is probably necessary in 
order to distinguish that two are present, though the point may 
be easily seen by means of dissection. The first abdominal gang¬ 
lion would hardly be looked for in the thorax A 
Eeproductive System.— The only traces of reproductive or¬ 
gans found in the larvae are ovaries and testes in the 
early stages of development. These lie in the fourth and fifth 
segments, and are found only in the large larvae which are pre¬ 
paring for pupation, which period is determined by the addition 
ovaries, which are easily distinguishable, are elongate bodies, 
* A dissection of a species of Molanna has since been made and the 
ganglia found substantially the same as in P. designatus. 
