Dugesia polyahroa (0. Schmidt, 1861) 



Synonyms: Planaria polyahroa Schmidt, 1861; P. lugubris: Bbhmig, 1909; 

 Dugesia lugubris: Ball, 1969 (in part). 



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Fig. 16 after Bohmig (1909). 



Mature specimens up to 20 mm long and about 3 mm wide. Head more or less 

 rounded, occasionally showing a small median projection. A gentle nar- 

 rowing or neck behind the lateral edges. Eyes usually two, close to the 

 frontal end. Color variable, usually a shade of brown, either uniformly 

 distributed or somewhat spotty. A pair of lighter elongated auricular 

 sense organs is seen near the lateral margin of the head some distance 

 behind the eye level. Pharynx unpigmented. Testes numerous, dorsal, 

 extending to posterior end. The penis consists of a very muscular bulb 

 and a generally conical papilla. The bulb is divided into two sections, 

 an anterodorsal part which contains the rounded anterior seminal vesicle 

 and a posterior part enclosing the elongated posterior seminal vesicle. 

 The two vesicles are joined by a narrower canal. From the posterior ves- 

 icle the ejaculatory duct proceeds through the papilla to its tip. The 

 vasa deferentia open separately into the anterior seminal vesicle, the 

 two oviducts into the posterior part of the bursa stalk. Reproduction 

 only sexual. Cocoon spherical, stalked.' This species, widely distrib- 

 uted in Europe, has been introduced to the St. Lawrence River system in 

 eastern Canada (Ontario) and New York State. Principal literature: 

 Bohmig (1909), Komarek (1925), Ball (1969), Reynoldson and Bellamy 

 (1970). 



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