308 Dr. Johnston on the Irish Annelides. 



more or less iridescent. Head concealed by the front scales, 

 small, tumid, somewhat heart-shaped, sinuated in front, 

 smooth and flesh-coloured ; eyes 2, very distinct, round and 

 black, placed far back on the occiput and remote from each 

 other : antenna 3, the mid one originating in the sinus of the 

 head, large and equal in length to the palpi, setaceous with 

 an abruptly acuminated point, downy, of a dusky colour, but 

 pale and jointed at the base; the lateral antennae are only 

 about a third the size of the odd one, and of the same 

 form and structure. Palpi 2, awl-shaped, larger than the 

 odd antenna, downy or ciliate, and of a straw-yellow colour. 

 On each side of them there is a pair of tentacular cirri equal 

 in length to themselves, but not so stout, and in every respect 

 resembling the mid antenna. Mouth inferior, terminal, fur- 

 nished with a protrusile proboscis, armed with 4 jaws of a 

 horn colour, and encircled at the orifice with a series of short 

 conical papillae. Segments numerous, narrow, deeply incised 

 on the sides, broader than deep. Scales deciduous, rather 

 small, roundish, smooth, with a plain unfringed edge, of a 

 greenish-grey colour, irregularly clouded, and covered with 

 pale puncture-like dots. In all our specimens some pairs 

 had been lost. Audouin and M. Edwards say there are 15 

 pairs, and they are affixed to every alternate segment after 

 the fashion of the more normal species of the genus. The 

 anterior pairs are imbricated and cover the back entirely, but 

 the posterior pairs lie over the bases of the feet, and leave 

 the back naked in the middle. Feet well developed, homo- 

 logous ; the dorsal branch represented by a mere tubercle, 

 from which grows a fan-shaped brush of short stout equal 

 bristles ; the ventral branch conoid, protruded much beyond 

 the dorsal, obliquely truncate, armed with a series of golden- 

 yellow strong bristles, and with a small inferior cirrus which 

 does not extend beyond the apex. Bristles of the dorsal branch 

 somewhat curved, rather obtuse, rough on one side, and ge- 

 nerally soiled with extraneous matter ; those of the ventral 

 branch more than twice as long, decreasing both in strength 

 and length as the series descends to the belly, the two upper 

 ones pointed like a lance, the rest like a hedge-knife, with 



