I 24 COE AND KUNKEL. 



The brain and the csopliageal, dorso-niedian and lateral nerves 

 are as in related species. The proboscis nerves of which there 

 is a single pair arising from the ventral ganglia, near the origin 

 of the ventral commissure, are remarkably large and conspic- 

 uous. As seen in Fig. 2, they enter directly into the ventral 

 wall of the proboscis at its attachment to the tissues of the head 

 (immediately in the region of the dorsal brain commissure) and 

 then pass into the midst of the longitudinal muscles of the pro- 

 boscis where they divide into a number of smaller nerves. A 

 short distance behind the brain these spread out into a plexus 

 beneath the epithelium, as in other species in which the inner 

 muscular layer of the proboscis is wanting. The three slight 

 pits on ths tip of the snout, representing \h& frontal sense organs, 

 are comparatively well developed. Cerebral sense organs are also 

 highly developed, and exhibit the usual structure and relations 

 with the dorsal ganglia and the cephalic furrows. 



The sexual glands, which alternate with the diverticula of the 

 intestine, become mature in midsummer. The genital ducts, when 

 fully formed, open through the muscular layers to the dorso- 

 lateral aspects of the body as in related species. 



