1900.] POLYNOID FROM NEW ZEALAND. 975 



recognized its proper genus ; in preference to the specific name 

 conferred by Quatrefages, who had most unaccountably referred 

 it to Aphrodita. 



The most striking and interesting feature about the Annelid is 

 the very definite, subelytral groove along the back (Plate LX. fig. 3) 

 with the row of tubercles for the support of the overlapping 

 moieties of the elytra, so that the groove is constantly open for the 

 respiratory current. I am not aware that anything so definite 

 has been hitherto noted in any Polynoid, and I suggest the term 

 " respiratory channel " for it. 



The definite " exhalant aperture," too, formed by the emargina- 

 tions of the last pair of elytra (Plate LX. fig. 1) complete the utility 

 of this channel. The presence of such an aperture formed in this 

 way is mentioned and figured by Huxley for L. squamatus, in his 

 < Manual of Anatomy of the Invertebrates,' 1877, p. 228. The 

 peculiar hair-like character of the neuropodial bristles — suggesting 

 the felted hairs of Aphrodita — are also a peculiarity of the species, 

 especially in their number and softness of texture. 



Description of the Species. By W. Malcolm Thomson. 



General appearance. — The specimens measured in a preserved 

 condition ranged in length from 80 mm. downwards and in breadth 

 from 35 mm. Average specimens were about 68 mm. long by 

 25 mm. broad. In shape the animal is a very regular oval, the 

 anterior end being rather narrower than the posterior. The upper 

 surface of the body is strongly convex, both in the longitudinal 

 and transverse planes, the ventral surface being flat or even 

 inclined to be convex, but with the usual median groove. The 

 dorsum is completely covered by the large imbricate elytra, of which 

 there are twelve pairs (Plate LX. fig. 1). Between the first pair a 

 small median notch allows the protrusion of the palps and tentacles. 

 There is a smooth tract over the mesial moiety of the series of 

 the elytra, bounded on each side by a row of oblong transverse 

 ridges representing the areolae or areas of attachment of the 

 elytra (Plate LX. fig. 1,«). The median moiety of each elytron 

 constituting this tract is coloured a warm brown, and this colour 

 is continued outwards behind the areola (Plate LX. fig. 1, c), 

 the anterior surface of which is coloured light buff and is smoother 

 than the general surface. The median tract ceases at the last pair 

 of elytra, the inner margin of each of which is notched, so as 

 to produce a small oval aperture with distinct, upturned lips: 

 this aperture is the exhalant respiratory pore, to which we shall 

 return. The posterior and lateral surfaces of an elytron are beset 

 with numerous spiny processes and also with fine hairs. The 

 margin of the body, as seen from above, is formed by a fringe of 

 hairs constituted by the successive bundles of notopodial bristles. 

 These hair-like bristles and the processes of the elytra collect 

 a considerable amount of mud and afford a foothold for foreign 

 organisms, which no doubt aid in the concealment of the animal. 



