JOURNAL OF ENTOMOLOGY AND ZOOLOGY 145 
large ganglia, similar to the branchial and genital, were visible, 
such ganglia as appeared being very minute. The genital 
plexus is greatly fused, forming a single ganglion as large as 
one of the buccal ganglia, which gives off several nerves to 
the reproductive organs, as well as one nerve (12) to the body 
wall, which is apparently homologous with (13). The branchial 
plexus consists of several fairly large ganglia, which give off 
larger nerves than are found in other portions of the accessory 
system. The central ganglion receives a nerve from the vis- 
ceral ganglion and branches from the posterior mantle nerve, 
these latter having passed through ganglia which give off 
branches to the heart and branchial region. The central 
ganglion gives off branches to the nephridia and the region 
around the intestine, and is joined to a small ganglion just 
above it, which gives nerves to the three branchie. 
Tuer Sense Orcans. The otocysts are buried between the 
cerebro-pleural and ,pedal ganglia, just inside the cerebro- 
pleural and pleuro-pedal connectives. They are oval mem- 
branous capsules about 50 microns long, lined with a few much 
elongated cells. The otoconia appeared to be very small par- 
ticles, but they may have been partly eroded by the acid used 
in the fixing solution. 
The eye is nearly globular and slightly elongated from front 
backwards, where it measures about 75 microns. It lies in a 
mass of connective tissue somewhat in front of the optic 
ganglion, to which it is attached by a very small nerve. The 
coat of the eye itself is a thin, compact, connective tissue layer, 
much thinner in front than in back. The lens is nearly oval 
and in section appears to be formed of a thick capsule, contain- 
ing an alveolar substance, or at least, a substance that con- 
denses into globules after fixation. Back of this is a thick 
cap-shaped layer of pigment granules, and back of these and 
closely connected with them are a few cells of rather indefin- 
ate outline, containing large granular nuclei, very similar to 
the nuclei of some of the nerve cells. The whole appearance 
and location of the eye would indicate that it does not fulfill 
any very important function. It is not only situated below the 
