460 TEANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



specimens examined was there any tendency to the devel- 

 opment of brown pigment on the head. 



Most of the specimens taken measured from 1 to 2 cm. 

 in length ; many had well developed genital organs. In 

 shape they resembled T. inelaiioceplialum, the more 

 spathulate head distinguishing them from the littoral form 

 dealt with above. The colouring was fairly constant ; 

 the majority were a more or less deep apricot-yellow, a 

 few were of a rather more greenish or brownish tint and 

 one flesh-coloured individual was noted. In all a con- 

 spicuous oblong patch of opaque white flakes was placed 

 transversely between the anterior and posterior pairs of 

 eyes, from which in most cases a median longitudinal line 

 of similar white flakes extended back along the dorsal 

 surface, generally the whole length of the body. The 

 eyes were black, well defined usually and aboat equal in 

 size, the posterior pair being often somewhat closer 

 together than the anterior in the well extended animal. 



In the character of the proboscis they agreed with the 

 more typical T. canclldiun from the shore rather than 

 with T. melanocephalum, the stylet of the central appara- 

 tus being on the whole longer in proportion to the handle 

 than is the case in the latter. Much stress cannot, 

 however, be laid on this point, for the stylet apparatus, 

 especially the handle, varies so much in form as to be of 

 little value in discriminating between such closely allied 

 species as T. cafuUdiim, T. vermiculatum and T. mela)io- 

 cephalicm, though sufficing as a general rule to distinguish 

 these three as a group from otlier Enoplous Nemertines. 



Mention may here be made of two or three brownish 

 yellow Nemertines agreeing fairly well in general appear- 

 ance with Tetrastemmct cancUdiim, but having the handle 

 of the central stylet very long, its posterior border being 

 straif^ht with rounded corners, thus resemblin^r in outline 



