204 



to the gliding movements common to such forms. The worms also move 

 after the looping fashion of measuring worms, and some other triclads, 

 the ventral surface between the two auricles and the median posterior 

 ventral region acting like suckers as the worm loops along. This move- 

 ment is very rapid and although they often move by gliding, this other 

 motion is used much of the time. The action of the anterior adhesive 

 region was studied from the dorsal side along with the auricular append- 

 ages. When the animal extends its anterior end for a new hold, the 

 auricles are obliterated and the contours of this end of the body are as 

 shown by the figure 6. When the adhesive ventral surface takes hold 

 it is as though the middle portion of the anterior end between the suckers 

 contracted and left the corners of the head expandel (Fig. 5). The 

 middle region seems to contract and roll under in front so that at one 

 stage there is an appearance which resembles the horn- like tentacles 

 shown in Verrill's figure of Procerodes ulvae. While the anterior end 

 holds and the posterior is freed and then drawn up, the auricles project 

 straight out in front, being then extended to their maximum length 

 (Fig. 5). At the blunt posterior end there is sometimes a suggestion of 

 a notch in the margin at the point where the sucker would be located 

 on the ventral side. 



The main trunks of the water vascular system and their branches 

 were observed. The pharynx occupies the position shown in the figures 

 1 and 7, which also show something of the gut lobes at the anterior 

 and posterior ends. The main posterior divisions of the gut are so clo- 

 sely applied that I at first thought them continuous, as in SyncocUdium 

 I >d lucidum. A careful study, however, made it clear that they are only 

 closely pressed together. 



The ovaries were readily made out in the fresh specimens at the 

 points indicated on the figure 7 at (T) and also the testes. The vasa defer- 

 entia, penis and uterus could be dimly seen posteriorly (Fig. 7). Certain 

 silvery lobes among the lateral gut lobes were probably its yolk glands. 

 The larger worms only showed reproductive organs. 



I have attempted in the foregoing merely to put my scattered notes 

 in a connected form without venturing any additional interpretations on 

 observations made so long ago. These notes were sent to Dr. Wilhelmi 

 with my full permission to make any use of them he chose. He pre- 

 ferred, however, that I should plublish them along with a note from him 

 upon the distribution of G. segmentata. 



Zoological Laboratory, University of Missouri. Culumbia, Mo., U. S. A. 

 March 15 th 1908. 



