Longitudinal 

 / views \ 



— Prostomium — 



SETAE 



Peristomium 



/ 



Segment II 



Pharyngeal 

 gland 



Hair seta 



Dorsal blood 

 vessel 



Ventral vessel 

 Nerve cord 



Gut 



/i( 



//I 



^kr Dorsal setae 



k'',.''..'>':'<'.n*/>*>--^ 



Anterior 

 sperm sac 



Testisi 

 Spermatheca 

 Clitellum 



Ovary 



Vas deferens] 



Atrium 



Penis— 



Prostate- 



Penial seta 



Female, 

 funnel 



-^ 



Brain 



Pharynx 



hair 



b: smooth 



lateral 

 hairlets 



serrate 



upper tooth 



round simple 



bifid 



Figure 2. — Left, exterior of anterior portion of an oligochaete; middle, interior view; right, 



basic types of setae. 



