MICRURA AURANTIACA. 201 



colouring it is one of the most striking of the group, the bright yellow patch in front and the 

 ever-varjing purplish lustre of the cilia on the deep brown body forming manifold contrasts, 

 at once pleasing and novel. It is active and voracious, and it is dangerous to leave two in the 

 same vessel, especially if there is disparity in size, as the stronger devours the weaker. Like 

 many of its allies, grave injuries are borne with impunity; thus a specimen which had been so 

 severely wounded in January that it divided itself behind the head, reproduced early in May a 

 small but complete body, furnished with the usual caudal styliform process, and this without a 

 single renewal of the sea-water in the vessel. The head had diminished much in bulk, but was 

 still the widest part of the animal. The body measured an inch and a half after nine months' 

 growth. The introduction of a fresh and hungry specimen from the coralline region proved fatal 

 to this example. The posterior end of the ruptured worm also lived many months, turning 

 slowly round on the bottom of the vessel, and showing a pointed process above the aperture of the 

 digestive chamber in front, while the ova in its interior had arrived almost at complete development 

 in April. 



Sir J. Dalyell procured the first specimen of this species from Shetland, and so introduced it 

 to science and our fauna. He also figures an example with reproduced (pale) anterior and posterior 

 extremities. Few authors seem to have observed this form, the above, indeed, being the only 

 published notice I have been able to identify. This is the more remarkable, as it has frequently 

 been sent from St. Andrews in the debris of the fishing boats on their return from deep 

 water. 



4. Micrura aurantiaca, Grube. Plate VII, fig. 4. 



Specific character. — Eyeless. A white patch at the tip of the snout. Body rounded, and of 

 a fine brick-red hue. 



Synonym. 

 1855. Meckelia aurantiaca, Grube. Archiv fur Naturges., p. 148, pi. 7, f. 1. 



Habitat. — Under stones in tide-pools to the north of Rat Island, Herm. 



Body. — Three or four inches long, rather rounded on the dorsum and flattened inferiorly. A 

 small caudal process or filament, as indicated in the figure, was noticed during delineation, but 

 this was not present when I examined it subsequently. 



Colour. — Dorsum fine brick-red, with a roseate lustre here and there from the cilia, and 

 having a white patch a little behind the anterior border of the snout. The reddish pigment in 

 front of the white spot is somewhat deeper in tint than the rest of the body. The under surface 

 is pinkish-white. 



Head, — Scarcely wider than the succeeding portion of the body, somewhat flattened, slightly 

 narrowed towards the front, and with rather shallow lateral fissures, the upper lip of the latter 

 projecting over the lower. No eye-specks are visible. The mouth forms an indistinct slit in the 

 usual position. 



In minute anatomy this species strictly agrees with the Lineidae. The cells of the cutis are 

 very distinctly marked, and the subjacent pigmentary region has a fine reddish hue on the dorsum. 



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