PI.ANARIA. 17 



a light-coloured line runs down the centre, and the margins are folded 

 so as to form almost a tube. There are two ventral pores, of which 

 the anterior is oral, and the posterior genital. Very active. 



The following are doubtful species of this family : — 



Planaria cuneus, wedge-shaped, the front widest and truncate, 

 greyish-brown. Length y. 



Planaria cuneus, Daly ell, Pow. Creat. ii. 121. pi. 15. f. 16, 17. 

 Hab. Blackball Pond, Daly ell. 



Desc. " Head obtuse, the corners rounded as it advances, and the 

 portion between them depressed. Body thick, flattened ; tail acute. 

 Colour greyish-brown. No eyes visible." — Dalyell. In the figure, 

 however, a single eye in front, midway between its angles, is distinctly 

 shown. The species is very like the Planaria truncata of Miiller, 

 which has four eyes. Oersted considers the latter to be synonymous 

 with his Vortex littoraliSy which he describes and figures with two 

 eyes {Entw. Plattw. 64). See also Dies. Syst. Helm. i. 229. 



Planoides fasca. 



Planoides fusca, Dalyell, Pow. Creat. ii. 123. pi. 16. f. 35, 36. 

 Hab. The sea-shore. 



Desc. "Length aline and a half; breadth and thickness nearly 

 half the length. Body compact, solid ; the anterior extremity 

 divided horizontally into two lips, wherein is perhaps the mouth. 

 This extremity is fashioned somewhat as a scoop by the fold of a 

 membranaceous edge, apparently reflected on the back. A dark red 

 internal organ is situate towards the centre of the body. Neither 

 eyes nor marginal specks have been discovered, nor any prominent 

 parts of external organization. Colour brownish, speckled. Motion 

 smooth and gliding." — -Dalyell. 



Planaria hirudo, body linear, lengthened, brown, marked in front 

 with a black point and line ; two pale spots above the circular tail. 

 Length 4'". 



Planaria hirudo, Johnston in Ann. ^ May. Nat. Hist. xvi. 437. pi. 15. 

 f. 3. Dies. Syst. Helm. i. 473. 



Hab. The littoral region amongst confervse. 



Desc. The body is of a uniform light brown colour excepting the 

 two pale spots near the tail, and, when fully stretched, is of a narrow 

 linear figure, slightly tapered in front. There is a small black dot 

 about half a line behind the anterior end, and a dark line runs from 

 it forward to the tip. These are not formed by an eye, or a cluster 

 of eyes, but the line seems rather to be produced by some internal 

 tube, and the dot by some harder, perhaps horny, substance. Very 

 active. Motion continuous. — Seems to be nearly related to the Pla- 



c 



