Plandria cmmuta. S45 



Desc. — Body oval, flat, thin, soft, the margin plane ; 

 length about three fourths of an inch ; the breadth about one 

 half the length. Dorsal surface reddish brown, freckled 

 with white dots ; the brown colour disposed in vein-like rami- 

 fications, very distinct towards the sides. In front there are 

 two conical tentacula, about one eighth of an inch long, fur- 

 rowed on the ventral aspect ; altogether marginal, darker- 

 coloured at the bases, from numerous very minute black dots. 

 About a line behind the tentacula there is an oblong black spot, 

 divided into two equal halves by the mesial [middle] line : this 

 spot is pointed in front, truncate posteriorly, and is formed 

 by a multitude of dot-like eyes clustered together. The me- 

 sial line itself is of a red or blood colour, but does not reach 

 to either extremity. Ventral surface also reddish-brown, but 

 lighter ; marked in the middle with an oblong white space, 

 produced by the retracted proboscis, which is short, white, 

 thick, exsertile, with a terminal wide and unarmed aper- 

 ture. Behind the spot produced by it there is another small 

 pore, but whether an anus or sexual orifice is uncertain. 



The red line which runs along the centre of the back is 

 evidently an alimentary canal ; and the vessels which ramify 

 through the body, and on which the colour of the worm 

 depends, appear to arise from it, and are probably intended 

 to convey the nutritive fluid directly to the different parts. 

 There is no appearance of any sanguineous system, but the 

 vessels just mentioned are branched in a somewhat dichoto- 

 mous manner, particularly towards the sides ; for they do not 

 reach tlie margin, neither do they seem to anastomose freely. 

 Their form and disposition are well expressed in the magni- 

 fied figure. 



Planaria cornuta is a new acquisition to the British fauna. 

 It inhabits the sea on the coast of Berwickshire ; where it 

 resides in deep water, and is, consequently, only to be found 

 occasionally creeping on corallines and shells brought up by 

 the lines of the fishermen. It progresses by a sliding con- 

 tinuous motion ; and, for a worm, its progress is not slow. 

 When in motion, the tentacula are generally erect or reflected 

 backwards ; it often moves on the side, with the ventral sur- 

 face half everted ; and sometimes both sides are turned up, 

 so as almost to meet. It dies soon in a vessel, although filled 

 with sea-water ; and, towards its close, will frequently project 

 the proboscis, or even detach it entirely in the struggle. But, 

 though separated, this part retains its irritability for an 

 amazing length of time. On the evening of the day on which 

 a fine specimen was brought me, I left it, lively and healthy, 

 in a saucer of sea-water ; but next morning it was found 



