480 Howard Edwin Enders. 



The "eyes" of tlie adult are frequently overlooked, bnt they were 

 clearly pointed out in Laffuie's monograph. One black eye-spot is 

 located on each side external to the antenna and directly beneath the 

 dorsally directed auriculate lobe of the ventral lips of the buccal 

 funnel. It is here less conspicuous than in the larva. The dorsal 

 eyes of the larva are not demonstrable in the adult individuals. 



The middle region. — The middle region is situated immediately 

 back of the ninth setigerous segment, and communicates with it by 

 a narrow cylindrical region little thicker than the ventral muscles 

 themselves. It is conspicuous because of the diversity in the form of 

 the segments and for the dark green color of the intestine as seen 

 through the transparent integument which covers the dorsal side of 

 the body. 



The number of segments in this region of the body is disputed by 

 various workers. De Quatrefages and Jourdain include the twelfth 

 segment, with its large aliform notopodia, in the middle region, but 

 Laffuie accepts the former view ''as being the most natural." More 

 recently (1897) Ray Lankester published a figure in which he in- 

 cludes the twelfth (his eleventh) segment in the anterior region, but 

 it may have been drawn in conformity with the views of Lespes and 

 Cosmovici. My observations upon the extent of the oesophagus and 

 its transition into the dilated green portion of the gut, both in the 

 adult and the transforming larva, confirm the opinions of Laffuie 

 and Jourdain. I shall, therefore, regard the twelfth segment as a 

 part of the middle region, which is made up of five segments. Of 

 these the last three segments have the form of "fans" or "palettes," 

 and consist, according to Laffuie, of the fused notopodia and neuro- 

 podia of their segments. The thirteenth segment (second of the 

 mid-region) is usually described as consisting of a ventral and a 

 dorsal sucker, but I shall call the "dorsal sucker" or "dorsal cupule" 

 an accessory feeding organ for reasons that follow in another chapter. 



The fAvelfth segment (first of the middle region) on the dorsal 

 side bears a pair of large fiattened aliform notopodia. When they 

 arc extended at right angles to the long axis of the worm their out- 

 line forms a tall isosceles triangle whose base joins the walls of the 

 body. The distal fourth of their dorsal margin bears a small spatu- 



