FREE-LIVING FLATWORMS 



Occurrence. — Northeastern states, New York, Michigan. 



2. Turbellarians whose intestines have three main branches, 

 one running forward through the center of the body and two 

 which turn backward on each side of the pharynx. Order 

 Triclada. 



3. Turbellarians with one pharynx. Dendroccelum, Plan- 

 aria. 



,^ vtji-jsics-vs:^ 



Fig. 97. — Milky planarian, Dendroccelum lacteum. 



Milky planarian, Dendroccelum lacteum. — These beautiful 

 planarians are creamy white with their food canals showing in 

 a tracery of brown (Fig. 97). Just behind the eyes there 

 is a constricted necklike region which makes the rounded 

 auricles more prominent. 



These pale planarians crawl over the stones in shallow 

 streams. An occasional one can be found there throughout 

 the winter (PI. I). When collected such animals sometimes 

 lay their hard-shelled winter eggs shortly after they are 

 brought into the house. They are about the size of a mus- 

 tard seed, shiny, chestnut brown and raised on a tiny stalk. 



Occurrence. — Eastern states. 



Fig. 98. — Planaria maculata. 



Planaria maculata. — Planaria maculata is one of the 

 commonest planarians (Fig. 98). Its body is slender, 

 about one quarter of an inch long, and tapers into a 

 pointed tail. The head is broader than the body, and pointed 



125 



