1917.] NATURAL SCIENCES OF PHILADELPHIA. 139 



its entire extent by a slender foot. Dorsally it carries a ninnber of 

 lappets in two longitudinal series attached along the junction of 

 the dorsal and lateral surfaces of the body. All of the specimens 

 in hand were preserved in formaldehyde, and while this served 

 admirably to preserve the general appearance and proportion of 

 parts, practically all of the lappets were found to be detached when 

 the material was unpacked for study. It is certain, however, that 

 each lappet is attached to the body by a slender stalk, and is leaf- 

 like in form. The only doubtful point concerns their exact number. 

 Judging by the slight circular scars where they were attached to the 

 body, there appear to be five on the left side and four on the right, 

 the place of the second largest one on the right being occupied by 

 the anal opening. In a few large specimens there are traces of an 

 additional, very small pair near the posterior end of the body. Each 

 is penetrated by ramifications of the liver branches and by a system 

 of blood sinuses. 



The genital openings are on the right side of the body in the neck 

 region, while the anal opening is far removed on the dorsal side of 

 the animal. 



Internal Anatomy. — In this species no distinct visceral cavity or 

 spacious primary body cavity exists, the various systems of organs 

 being surrounded by a loose meshwork of connective tissue and 

 muscle fibers with the intercommunicating spaces serving as blood 

 sinuses. Dissection accordingly is a comparatively simple matter, 

 and the different systems of organs, especially the nervous, have 

 been traced out in considerable detail. A description of each of 

 these will now be given. 



Considering first the digestive system, we find that the posterior 

 border of the snout is deeply cleft along the midline, and, lacking 

 the larger tentacles at this point, forms the ventral border of the 

 mouth opening. The remaining margin is fashioned into thick, 

 swollen, glandular lips united anteriorly, and of such length that the 

 mouth appears as a longitudinal slit three or four millimeters in 

 length. 



The esophagus or pharynx (PI. XI, fig. 4) is a comparatively short 

 tube, and owing to the ventral position of the mouth the dorsal wall 

 is considerably longer than the ventral. Immediately beyond the 

 mouth opening the walls are relatively thick and without folds, but 

 as the brain region is approached the inner lining becomes thinner 

 and is thrown into numerous longitudinal folds. Probably not less 

 than a dozen digestive tracts were either sectioned or opened care- 



