510 F. W. GAMBLE. 



arise on each side of the main-gut, and are of a brilliant carmine 

 colour at first, becoming much less conspicuous towards the 

 periphery. The pharynx and genital organs appear as white 

 patches round the main-gut. The mouth is placed in front 

 of the brain. The gut-branches do not anastomose. Eyes 

 are present at the bases of the tentacles, and two sharply 

 defined cephalic groups converge at the anterior end of the 

 brain. The position of the genital apertures has already been 

 mentioned. The male pore lies in front of the female. 



Habitat. — Between tide-marks, Greve d'Azette, Jersey 

 (Kohler) ; Plymouth Sound, 5—20 fms. (F. W. G.) ; Port 

 Erin, Isle of Man, 12—15 fms. (W. J. Beaumont and F. W. G.). 



Distribution. — Island of Lussin, Adriatic (Grube), Naples 

 (Lang). 



After much consideration I have referred several specimens 

 dredged at Plymouth and elsewhere to this species. The dis- 

 tinguishing points are the position of the mouth in front of 

 the brain ; the male genital aperature underneath the anterior 

 end of the pharyngeal sheath ; and the short, sharply defined 

 group of eyes over the brain. 



70. Oligocladus auritus (Claparede). 



1861. Eu RY LEFT A AUBITA, Claparede (35). 

 1884. Oligocladus aueitus, Lang (54). 



Length 18'5 mm. Body oval, transparent, white, the intes- 

 tine bright reddish-brown. Mouth in front of the brain. 

 Pharynx cylindriqal. Main-gut gives rise to three pairs of 

 secondary branches, which do not anastomose. Eyes are pre- 

 sent in and round the bases of the tentacles, but, according to 

 Claparede, are absent over the brain. The male genital 

 pore occurs just behind the mouth; the female aperture is 

 described by Claparede as almost central. Lang suggests 

 that this author probably mistook the sucker for the pore. 

 The vasa deferentia are scarcely so swollen as in O. san- 

 guinolentus, and the vesicula seminalis rather larger than 



