EXPLANATION OF PLATE XVIIL 



Figure 89. — Brancliiobdella Eavenelii, (p. 624;) dorsal view, natural size. 

 90. — Malacobdella obesa, (p. 625;) dorsal view. 

 91. — Pontobdella rapax, (p. 625;) dorsal view. 

 92. — Phascolosoma caementarium, (p. 627;) lateral view. 

 93. — P. Gouldii, (p. 627;) lateral view, reduced one-haljf. 



94. — Pontonema marinum, (p. 634 ;) female, lateral view, enlarged 15 diam- 

 eters ; 0, eggs ; v, genital orifice. 



(Figure 94 was drawn from a living specimen, by A. E. Verrill ; all tlie others were drawn from pre 

 served specimens, by J. H. Emerton.) 



