GENETYLLIS HIBERNICA. 97 



a brilliant chrome-yellow throughout. Dorsal cirrus unequally cordate, broadly lanceolate, 

 longer posteriorly than anteriorly, and marked by a series of lines and reticulations from 

 a central rib. The ceratophore is a massive short and bluntly-conical process. Imbricate 

 cirri borne more or less horizontally, leaving the centre of the dorsum bare. Setigerous 

 region short, bifid, supported by a black spine, and carrying shorter bristles than in 

 G. lutea, with shorter terminal processes. 



Habitat. — Procured on a stone coated with corallines, a yellow sponge, and several 

 Ascidians brought up by a fisherman's hook in the Minch, August, 1865. 



Head rounded ovate, with two black eyes of considerable size. The four tentacles 

 had been lost before minute examination, but they probably conform to those of the 

 previous species. The tentacular cirri are similarly arranged — two shorter anterior and 

 two longer posterior. 



Body about three inches in length, much tapered anteriorly. Posteriorly it terminates 

 in two caudal cirri. The dorsal surface is convex, the ventral marked by the two raised 

 lines on each side of a slightly depressed central area. The proboscis is enclosed. 



The entire animal is of a most brilliant chrome-yellow colour, deepest on the middle 

 third, which here and there shows blackish-brown patches on the lamellae. It tinged the 

 water with a yellowish mucus, and also dyed the spirit in which it was immersed of the 

 same hue. 



The dorsal region of the foot (Plate LXVIII, figs. 20 and 21) has a massive short 

 bluntly-conical process, devoid of spine or bristles, and bearing the unequally cordate 

 lamella, which is marked by a series of lines and reticulations from a central rib. The 

 imbricate lamellae are borne more or less horizontally along the sides of the dorsum, 

 leaving the central part bare. The semicircular gap at the base of the lamella fits the 

 rounded extremity of the division to which it is attached. The short setigerous region is 

 bifid at the tip, and supported by a black spine and a group of bristles, shorter than in 

 G. lutea (Plate LXXVII, fig. 14), and with translucent shafts, slightly bent, and with a 

 dilated distal end, which has a few spikes on each side. The terminal process is finely 

 tapered, and shorter than in G. lutea. The edge shows no distinct serrations, though the 

 adherence of particles would indicate them. Attached to the ventral and posterior parts 

 of the region is an irregularly reniform lamella (ventral cirrus), vertical in position. The 

 inferior border is rounded, but the superior is truncated and with a tendency to a point 

 at the upper and outer angle. The cirri, both superior and inferior, vary a little in shape 

 throughout the body. 



The stone on which it was brought up had a yellowish sponge on part of its surface, 

 but the connection between the Annelid and it is unknown. It crawled actively amongst 

 the Ascidians and other growths to escape capture. 



3. GrENETYLLis hibernica. Plate LVIII, fig. 8— head ; Plate LXIX, figs. 1 and 2— feet; 



Plate LXXVII, fig. 15— bristles. 



Specific Characters. — Head rounded ovate; eyes two, black and of considerable size; ten- 

 tacles and tentacular cirri as in allied forms. Body linear, about one inch long, terminating 



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