724 Henry B. Wäed, 



shown by the figures which indicate the canal pore always on the 

 bare surface and this is in precise agreement with the extended 

 observations of Lönnberg. This may be passed by with other smaller 

 iteras as a lapsus calami, and a few words devoted to a critical 

 examination of the general position taken by Kofoid and Watson 

 since it is all important to determine whether they are justified in 

 reversing the hitherto accepted orientation. Their argument is 

 evidently three fold being based on, 1) homology with the Hetero- 

 cotylea, 2) activities of the living worm, and 3) structure of muscle 

 and nervous Systems. The iirst point, being only an interpretation 

 can not be given great weight of itself, and furthermore might be 

 conceded without jnstifying any change in the accepted terminology. 

 On the second item I can offer no personal evidence but must call 

 attention prominently to the observations of Lönnberg which are 

 extended and apparently not in accord with this view. On the last 

 point what has already been said regarding the muscles indicates 

 a possible confusion in the paper under consideration. All of the 

 figures given in my plate (Figs. 11, 12, 13) are similarly oriented. 

 In all sections the muscle layer near the plane surface is so promi- 

 nently developed as to suggest a creeping organ analogous to the 

 Gastropod foot. Finally the canal pore lies on the convex surface 

 near which the canal is seen in section (Fig. 13) and opposite to 

 the well-developed muscular mass. Perhaps it is wise to call attention 

 to a certain unnaturalness in orienting this form with the convex 

 surface as ventral. While Watson is not specific on this point, and 

 does not figure any sections, yet I can hardly doubt that the 

 specimens she handled showed the same form that characterizes 

 every one of mine from the same host. But leaving this entirely 

 aside. I am unable to find any support in the structure of the worm 

 for the view advanced by Koeoid & Watson and do not feel that 

 they have given due consideration to the evidence adduced by 

 Lönnberg. My demonstration that the major development of the 

 musculature lies near the surface heretofore regarded as ventral 

 and not on that which they designate by this term, coupled with 

 the fact that Watson places the canal pore on the surface "in- 

 variably" covered by the lateral folds, impel nie to reject their 

 interpretation and to adhere to the views of Wagener, Lönnberg 

 and other previous investigators. 



One may readily recognize four regions of the body as 

 follows: 



