CONTRIBUTIONS TO THE ANATOMY OP THE HIRUDINEA. 491 



specimen, and they may be incomplete — a series of funnels or 

 of external apertures, or both, may exist. Pontobdella 

 presents a condition where the network remains connected 

 throughout the body, the funnels and external apertures ex- 

 hibiting a segmental arrangement. Woodcut, fig. 8, a, repre- 

 sents diagrammatically a portion of the nephridial network in 



fe 



B 



C 



Fig. 8. — Diagrams of the nepbridia in: — a. Pontobdella (two con- 

 tiguous nephridia are shown). B. Hirudo. c. Clepsine. a,a. Fun- 

 nels, b — c. Ducts in " testis-lobe." c — e. Ducts in " main lobe." 

 d. In Hirudo, ducts in coecal end of "main lobe." e—g. In Hirudo, 

 ducts in the "apical lobe." g. The apex, e — I. In Clepsine; and 

 g — /, in Hirudo, unbranched duct passing to the external aperture /. 

 j — k. In Hirudo, the vesicle, a?, x. Ccecal ductules in Pontobdella. 



