144 JOURNAL OF ENTOMOLOGY AND ZOOLOGY 



nerves, which differ in size and distribution. The one on the 

 left side (13) is small and runs directly back to the body wall, 

 while the one on the right side (11) is large and runs to the 

 genital ganglion, one of the branches of which (12) corresponds 

 in distribution to the whole left nerve. 



The visceral ganglia are situated back of the pedal, just 

 below the pleural, to which they are closely attached. The right 

 is larger than the left (about 100 microns in diameter) but 

 there is a distinct ganglion which sends a small nerve (25) to 

 the mucus gland. This is a slightly different arrangement than 

 any observed by Elliott, or Hancock and Embleton, as they 

 figure only one visceral ganglion, the right, which they consider 

 a fusion of the various visceral ganglionic centers. The right 

 visceral ganglion sends off three nerves, as does the unpaired 

 visceral ganglion of other species, but two of these are ex- 

 tremely small. The shortest (19) goes back along the albumen 

 gland, to which it gives nerves and finally enters the liver- 

 mass near the oesophagus. The next in size (20) gives off a 

 branch (21) which goes in the direction of the genital ganglion, 

 although I was not able to determine whether it actually joins 

 this ganglion. The main nerve then continues back beside the 

 posterior pedal nerve, giving off branches to the mucus gland, 

 then changes its course, gives a branch to the intestine, and 

 finally divides into two branches, one going to the hermaphro- 

 dite gland and the other to the nephridia. The largest nerve 

 (18) gives branches to the aorta and blood gland, continues 

 back beneath the heart, to which it gives a branch, gives 

 branches to the neiJhridia, and nephridial valve, and finally 

 joins the central ganglion of the branchial plexus. 



The optic ganglia are very small (about 50 microns) ovoid, 

 and attached to the upper surface of the cerebral by short 

 connectives. They give otf very minute nerves to the eyes. 



The accessory nervous system was only determined in certain 

 portions, since the nerves are very fine and run in a complex 

 mass of muscles, connective tissue, and glands, and special 

 methods could not be employed because of lack of material. 

 The gastro-heptic plexus is apparently much reduced, as no 



