INTERNAL ANATOMY 417 



thought arises from the fact that the main sole appears "bow-legged," 

 as it were. Such apparently suitable thin and narrow forms of sub- 

 stratum occur on certain marine algae and, as a matter of fact, at 

 least two observers Cobb and Chambers have seen Draconema per- 

 ambulating the surface of algae. 



In balsam specimens from Hudson Bay the body-wall tissues sur- 

 rounding the mouth-opening have a golden yellow color and take on the 

 form of a six-parted, but twelve-pointed, star. 



Probably the excretory pore is at the lips. I formerly referred to a 

 cell just behind the cardia as possibly representing the renette; this 

 suggestion may not be well founded. In this region I observe two of 

 these cells lying side by side in sub ventral position (see Fig. 1), sepa- 

 rated by a small space. In the same latitude, just behind the minute 

 cardiac cavity, on each side of the intestine, there is a rather compact 

 group of granular cells containing about a dozen nuclei. These groups 

 are as long as the corresponding body diameter, and about half as wide 

 as long. Between the two groups, on the dorsal side, there is a pair of 

 subdorsal granular cells rather closely resembling the subventral ones 

 just described. As to the function of these lateral groups of cells, it 

 seems not impossible, as they are free at their posterior ends and seem 

 connected with the intestine anteriorly, that they may be special 

 glands associated with digestion. There is a similar pair of lateral 

 groups of cells in front of the cardia, emptying (?) backward. I do 

 not think the possibility is excluded that some of these cells are nerve 

 cells. 



The intestine is composed of cells of such a size that about six are re- 

 quired to complete a circumference. The thin refractive lining is hardly 

 1 n thick. The cardia, as usual, presents a distinct group of closely 

 packed nuclei, indicating that it is composed of cells of rather small 

 size, of which the number is probably about fifteen to twenty. Notable 

 is the presence of scattered cells in the wall of the intestine which stain 

 differently from their neighbors. These, no doubt, discharge some 

 special function. Thus far they have been observed only in the an- 

 terior portion of the intestine. 



The portion of the neck opposite, and adjacent to, the oesophageal 

 constriction, except such portion as is occupied by the glands of the 

 minor sole, is rather closely packed with nerve cells. 



The lateral fields are one-third as wide as the body and contain 

 a considerable number of nuclei rather irregularly arranged. 



The cuticle in the posterior region of the tail is traversed by ra- 

 dial elements that give rise to a finely punctate appearance on 

 the surface (see Fig. 1). 



