174 TEANSACTIONS LIVEEPOOL BIOLOGICAL SOCIETY. 



III. POLYCLADLDA. 



A. ACOTTLEA. 



Family PlanoceeidvE. 



Stylochoplana maculata, Quatrefages. 



New to L.M.B.C. District. 



Two specimens, under stones, at low-water, in front of 

 the biological station. 



Length of my two specimens 11 and 13 mm. respectively, 

 body elongated ; broad and leaf-like in front, tapering 

 behind. Tentacles in the first fifth of body, the base of 

 each is surrounded by a circle, which in examination of 

 the living animal suggests a thickening of the epidermis, 

 and gives one the idea of a depression into which the 

 tentacle can be partly retracted. Five to seven eyes on 

 base of each tentacle ; between tentacles, and running 

 toward anterior margin are two groups of eight or nine 

 eyes, besides which, one of my specimens showed several 

 minute black specks intermixed with these intertentacular 

 eyes. 



Colour, to naked eye, greyish brown ; under microscope 

 the ground colour is yellowish-brown, with darker spots, 

 and a number of large white blotches, very well developed 

 in one specimen, but smaller and less clearly marked in 

 the other. Two genital openings are present. 



I kept both specimens under observation for some 

 hours, and noted that they swim with dorso-ventral flexion 

 of the whole body, much as the medicinal leech does ; and 

 if disturbed, when creeping on the wall of the vessel, 

 they retreat with a curious wriggling movement, which is 

 produced by the alternate use of the two sides of the 

 anterior end of the body ; the left anterior corner being 

 extended, and the body drawn up, when immediately the 

 right side is pushed forwards and the process repeated 



