212 ON SOME NEW OR LITTLE-KNOWN PARASITIC HIRUDINEI. 



Fig. 5. Tortuous course, loop, and return of water- vascular canal. 



6. Small black Pontobdella, parasitic on Bhinobatis. 



7. Spermatophore of the same. 



8. Black leech, with branchial leaflets and alveolated caudal disk, found on Myliobatis. 



9. Spermatophora of the same. 



10. Portion of the body of the same, slightly magnified. 



11. Inferior surface of the caudal disk, magnified to the same extent. 



12. Marginal portion of the disk, more highly magnified. 



13. White leech, with lateral branchiae, on conjunctiva of Green Turtle, New Caledonia. 



14. Larger specimen of the same species, Shark Bay, W. Australia. 



15. One of the branchiae, x 300 diameters.. 



