No. 2.] A ATA TOM V OF A SPECIES OF PLATYASPIS. 65 



the position indicated in Fig. 2, the same position as that 

 assigned to it in P. lenoiri, in Aspidogaster, and in Sticho- 

 cotyle. Two distinct passages lead posteriorly from this com- 

 mon opening, the male and the female ducts. These have 

 not been followed back so as to enable me to base their identifi- 

 cation upon a connection, respectively, with the spermary and 

 ovary. However, I feel tolerably sure that the one on the 

 right side is the male passage and that on the left the female, 

 as indicated in Fig. i. The latter contains a small number of 

 oval chitin-enclosed capsules, usually about six, which I am 

 inclined to regard as embryos. They are conspicuous in total 

 preparations, and in sections the chitinous capsule is seen sur- 

 rounding a mass of protoplasmic nucleated cells. These objects 

 are, apparently, identical with similar structures located in the 

 passage leading to the uterus in Poirier's figure (PI. XX, Fig. i). 

 According to that figure the passage is one which leads directly 

 from the ovary, and receives a duct from the yolk gland and 

 vitellaria in its course. The objects in the duct are very differ- 

 ent indeed from the embryos of most flukes, including the 

 innumerable small embryos of the closely allied Aspidogaster ; 

 but their situation and their chitinous covering are so identical 

 with those of the fluke embryos at large that there can be no 

 doubt that these are embryos, but extremely interesting from 

 their unusual size. It is obvious that in Platyaspis we have to 

 do, not with an immense number of small embryos, as in the 

 flukes generally, but with a few large ones. 



If we accept the view that these objects are embryos, we are 

 then able to identify the passage containing them as the vagina, 

 an identification which locates that organ as it is located in 

 P. lenoiri and Aspidogaster, but not in Stichocotyle, where 

 it is on the right side (Nickerson, '94, p. 477)- I might add 

 that it is some additional evidence in favor of this identifica- 

 tion that the wall of the organ agrees histologically with that 

 of the homologous organ of Aspidogaster. 



The other of the two passages opening at the genital pore is 

 thus indicated to be the cirrus organ, the terminal portion of 

 the spermiduct. In favor of this view, in addition to the points 

 mentioned in connection with the identification of the other as 



