170 



PLATHELMINTHES 



P. inquilina Wheeler (Fig. 275). Body oval, 6 mm. long and 4 mm. 

 wide; edges remain in contact with the surface over which the animal 

 is moving; color grayish: Vineyard Sound, mantle cavity of Fulgur. 



Fig. 275 Fig. 276 



Fig. 275 — Planocera inquilina (Wheeler). 1, tentacle; 2, intestine; 3, mouth; 



4, male genital pore ; 5, female genital pore. Fig. 276 — Stylochus 



ellipt icus {Yevrill). 1, tentacle ; 2, mouth. 



2. Stylochtjs Ehrenberg. Body oval or elliptical and flat; ten- 

 tacles short; pharynx with several accessory lobes; genital pores near 

 hinder end of body : 10 species. 



S. ellipticus (Girard) (Fig. 276). Body flat and thin w^ith undu- 

 lating margins, 20 mm. long and 6 mm. wide, yellowish-brown in color, 

 irregularly radially veined; tentacles small, white, each with a cluster 

 of ocelli ; 8 to 12 frontal and cerebral and numerous marginal ocelli pres- 

 ent: New England coast, the commonest of the larger 

 marine planarians, especially south of Cape Cod. 



Family 2. LEPTOPLANIDAE. 

 Body broad, flat, thin, without tentacles; mouth cen- 

 tral ; pharynx lobed ; usually 4 groups of ocelli, 2 cerebral 

 and 2 dorsal; marginal ocelli sometimes present; male 

 copulatory apparatus directed backwards: 4 genera and 

 about 60 species. 



Leptoplana Ehrenberg. Body foliaceous with undu- 

 lating edges; no marginal ocelli; genital pores rather 

 widely separated, the male pore being distant from the 

 end of the body: 25 species. 



L. variabilis (Girard) (Fig. 277). Body elliptical, 

 18 mm. long and 8 mm. wide, yellowish-brown in color; ocelli conspicuous, 

 the cerebral clusters containing about 30 each and the dorsal clusters about 

 15: New England coast, often abundant. 



Fig. 277 



Leptoplana 



variabilis 



(Verrill). 



