194 J- THOMAS PATTERSON. 



PLATE I. 



FIG. i. Horizontal section of a young specimen, showing the testes (<). seminal 

 vesicle (sv) which contains sperms, uterus (K), unicellular shell-elands (s), and the 

 germ-vitellarium (v). X 222. 



FIG. 2. Anterior half of a slightly oblique section from an adult individual. 

 The uterus shows a distinct, but small diverticulum (sr) which in all probability 

 corresponds to the receptaculum seminis of the other members of the genus. Note 

 that the testes have disappeared. X 222. 



FIG. 3. Horizontal section passing just below the intestine of a sexually ma- 

 tured individual. The section passes through the distal or bifurcated region of 

 the uterus (u), which contains spermatozoa, o, ovary; c, capsule containing two 

 eggs, one of which is giving off the first polar body; v, vitellarium. X 222. 



FIG. 4. Horizontal section of another sexually matured animal, but which 

 passes at a slightly lower level than the preceding. It shows clearly the bifurcated 

 region of the uterus; and also the relationship existing between the uterus, ovary 

 and vitellarium. X 222. 



FIG. 5. A longitudinal median section (slightly schrmuti/i-d) of a rather old 

 individual. It shows an advanced stage of the "female" condition, m, mouth; 

 pit, pharynx; oe, oesophagus; a, atrium; g, genital port-; />, penis; sv, seminal ve- 

 s, unicellular shell-glands; u, uterus; v, vitelline cell in uterus; c, capsules containing 

 embryos; /', intestine. X 117. 



