72 HENRY LESLIE OSBORN. 



between the testes in its course, in B. nodulosa the uterus is a 

 large sack containing old and young eggs indiscriminately, the 

 uterus is saccular even in young individuals of B. nodnlosa, as 

 seen in Looss' Fig. 10 of a specimen before egg production has 

 begun. The terminal part of the uterus differs decidedly from 

 the rest so as to form an entirely distinct though continuous 

 organ (cf. Fig. 2.) Its wall is very thick indeed and consists of 

 a strong muscular coat quite unlike the wall of the deeper parts 

 of the tube, and within the wall is furnished with a clothing of 

 very peculiar numerous long slender bluntly ending processes, 

 which are free at tip in the cavity of the organ. These structures 

 do not look like cilia, being too blunt. They do not seem certainly 

 to be protoplasmic, at least the bases do not seem as far as I have 

 been able to study them - - to be nucleated cells, as we should ex- 

 pect. The histological structure of this part will have to be left 

 for a subsequent study. This organ is further surrounded by 

 parenchyma cells having much the same appearance as the pros- 

 tate cells of the cirrhus. The eggs measure 0.07 mm. in length 

 instead of o. I mm. as in B. iwdiilosa. 



Laurer's canal is present, passes dorsally and opens to the ex- 

 terior on the left side. The seminal receptacle is large and dis- 

 tinct ; it lies close to and just behind the ovary. It is in all cases 

 of adults filled with spermatozoa. The vitellaria are large, and 

 located as above described laterally and so as partly to envelope 

 the intestines. They extend from near the phaynx to near 

 the hind end of the body and consist of very numerous small 

 follicles uniformly distributed. A duct from each crosses the 

 body in front of the anterior testis and behind the ovary and 

 seminal receptacle and the two joining from the yolk receptacle 

 which reaches the oviduct by a short duct close to the ovary. 



The points made in the foregoing pages are summarized in the 

 following table of comparisons : 



B. conntta. B. nodnlosa. 



Total length, 3 mm., 3 mm. Looss, 4.5 mm. 



Olsson. 



Body form, cylindrical, leaf-shaped. 



Neck, not prominent, prominent and distinct. 



