JOURNAL OF ENTOMOLOGY AND ZOOLOGY 39 
Returning now to the head region we find that the supra- 
esophageal ganglion is fused with the subesophageal in its for- 
ward region. wo prominent projections extend forward from 
the thickest mass of the ganglion from about the region of the 
connectives; these are the antennal lobes. From the ends of 
each of these the antennal nerve of each side takes origin and 
runs forward as a large trunk up into the antenna. From the 
slightly broader portion of the ganglion, above and quite near 
its connection with the subesophageal center at the base of the 
antennal lobe, laterally nerves on each side connect the brain 
with the group of large sensory cells of the postantennal organ. 
The connections and positions of these are very much like those 
deseribed by Becker 710, and shown in his Fig 27. These sense 
cells were much as described by this author. The little masses 
in these cells called by Becker ‘‘Zwischensubstanz’’, were very 
evident. These last usually stained almost as dark as the fat in 
various parts of the body. Back of the region of the post- 
antennal sense cells the broadest portion of the brain is reached. 
In this brain, as in one figured by Becker, the caudal end of 
the ganglion is tri-lobed with the middle portion slightly 
bi-lobed. 
The subesophageal ganglion caudad of the connectives with 
the brain separates more and more from the upper nerve center 
as the thoracic region is approached. The figure of Boettger 
compiled from sections of the head ganglia of Lepisma is not 
far from the condition of the centers of the head of Aphorwra. 
From the sides of the subesophageal ganglion three main nerve 
trunks take origin. These from the head end towards the 
thoracic region may be homologized as follows: mandibular, 
maxillary, and labial branches such as found in other insects. 
In the consideration of the supraesophageal ganglion no men- 
tion was made of an ocular branch or lobe, because there are 
no eyes and no ocular part of the brain was recognized. 
With some difficulty a clypeolabral trunk was distinguished. 
This nerve is rather small. It takes origin from the base of the 
antennal lobe near where it joins the supraesophageal ganglion 
and near the connective on each side. Its origin is more ven- 
