646 Illinois State Ldhordtorij of Natural History. 



Fi(i. 3. Placobdella rtigosa. Details of papillation, etc., of the right 

 half of the dorsal surface of somite XIX of a large example. The lines 

 to the right indicate the relative positions of the ventral furrows. X 5. 



Fio. 4. Placobdella parasitica. A. similar view of onehalf of somite 

 XIX, but of a much smaller specimen. X 5. 



Fig. 5. Hemiclepsis carinata. The principal features of the external 

 morphology of the dorsum of somites I to XII. Drawn mostly after a 

 specimen from Venice, Ohio, and very slightly diagrammatic. X 4.5. 



Fig. 6. Glossiphonia lineata. A slightly diagrammatic figure show- 

 ing the external morphology of the dorsum of somites I to X. The 

 annulation is originally derived from young; the sensillse and papillae 

 added as determined in adults. The young, X 30. 



Fio. 7. Hamopis maniiorati-s. Surface view of denticles from median 

 jaw. X 112. 



Plate XLUI. 

 A cti)! ohdella inequiannidata. 



Fig. 8. The dorsal external morphology of the entire leech (somites 

 XIII to XXI) omitted. Somewhat diagrammatic in that the furrows 

 are made to appear more regular than in the original. X 35. 



Fig. 9. Side view of the posterior end, showing the sucker with some 

 of its papillse projecting, x 35. 



Fig. 10. Outline of the sucker from below, with the circle of papill* 

 somewhat diagrammatically shown. X 35. 



Pig. 11. A small portion of the sucker rim showing the muscular ribs 

 and four of the papill*. The glandular ducts of the latter are stippled. 

 X 130. 



Plate XLIV. 



Philobdclla gracile. 



Fig. 12, 13. Dorsal and ventral views respectively of the anterior nine 

 somites, showing the chief features of external morphology. X 5. 



Fi(4. 14, 15. Ventral and dorsal views respectively of the posterior 

 end of the body; the dark spots are outlined. X 5. 



Fig. 16. The ventral surface of somites XII and XIII showing the 

 various features of the region of the genital orifices. A combination 

 drawing from several specimens. X 5. 



Fig. 17. Reproductive organs dissected and partly displayed. X 4. 



Fig. 18, 19. Posterior and anterior ends respectively from the left 

 side. X 5. 



Fig. 20. Surface view of a posterior portion of the tooth series of the 

 median jaw with the outline of the jaw partly shown. X 5G. 



Fig. 21. Female reproductive organs dissected and viewed from the 

 right side. From the same dissection as figure 12. X 4. 



