The male copulatory organ or penis is a muscular organ consisting of two 

 parts, the anterior penis bulb (pb) embedded in the parenchyma and the 

 penis papilla (pp) protruding into the male atrium. Generally the two 

 sperm ducts (vd) enter the penis bulb, separately or combined as a common 

 vas deferens, and open into a cavity, the seminal vesicle (vs) or bulbar 

 cavity. From this cavity a narrower duct proceeds into the penis papilla, 

 the ejaculatory duct (de) . There are, however, several modifications of 

 this plan found in the different species. 



The oviducts or ovovitelline ducts usually approach the midline above the 

 genital atrium and unite to form a common oviduct (ode) which generally 

 opens into the atrium from the dorsal side. A usually sac-shaped 

 accessory organ, the copulatory bursa (b) , lies in the space between the 

 pharyngeal pouch and the penis bulb and is connected to the atrium by a 

 muscular tube, the bursal duct or canal (bd) , running dorsal to the 

 atrium either in the midline or to one side of it. In a few species the 

 bursa is absent but the bursal canal is developed, either ending blindly 

 or connecting with a branch of the intestine. In the genera Cuva and 

 Dugesia, the paired or united oviducts open into the distal part of the 

 bursal canal instead of the atrium. 



Species of the genus Planaria have a hollow very muscular organ attached 

 to the posterior portion of the copulatory complex, the adenodactyl (ad) 

 or musculo-glandular organ. 



Gland ducts originating in the surrounding parenchyma open into various 

 parts of the copulatory complex: the penial cavity, the terminal parts 

 of the oviducts ("shell glands", sg) , the common atrium (cement glands), 

 the adenodactyl, etc. 



