PLATE I. 

 Glossiphonia stagnalis. x 20. 

 Fig. 1. Dorsal view of the first twelve somites. The positions of the 

 genital pores on the ventral side are also indicated. 



ng nuchal gland. 



Glossiphonia nepheloidea. x 56. 

 Fig. 2. Dorsal view of the first ten somites. 



Glossiphonia fusca. x 30. 

 Fig. 3. Dorsal view of the first ten somites of a young example, 

 showing the metameric sensillae and papillae. 

 Glossiphonia complanata. x 18. 

 Fig. 4. Dorsal view of the first ten somites. The paramedian stripes 

 are shown but the papillae and sensillse are omitted. 

 Placobdella montifera. x 13. 

 Fig. 5. Outlines of part of the reproductive organs, dissected. The 

 folds of the epididymis and ejaculatory canal are drawn 

 aside to show their length. A portion of the ventral nerve 

 cord is included to show the segmental position of the parts. 



at Atrium 



de Ejaculatory canal of the spermduct 



ep Epididymis 



ov Ovary or ovarian sac 



ti First testis 



vd Vas deferens 



Placobdella rugosa. x 5. 

 Fig. 6. Dorsal view of the first ten somites. All of the papillae and 

 most of the metameric sensillae are shown but not the color 

 pattern. 



Placobdella parasitica, x 5. 

 Fig. 7. Dorsal view of the first twelve somites. The dark colored 

 background is shown by stippling, the yellow vitta and spot 

 being plain. The papillae are omitted but the positions of 

 the genital orifices on the ventral side are indicated. 

 Fig. 8. Papillae and sensillae of the right half of the dorsal surface 

 of somite XIX of a medium-sized example. The lines to 

 the right indicate the relative positions of the furrows on the 

 ventral side. 



Placobdella rugosa. x 5. 

 Fig. 9. Papillae and sensillae of the dorsal surface of the right half 

 of somite XIX of a large example. The lines to the right 

 indicate the relative positions of the furrows on the ventral 

 side. 



