47 62 Proceedings of the Royal Irish Academy. 



Ehlers (torn, cit., p. 62) is of the opinion that these structures correspond to 

 the buccal cirri of the Polynoidae. It seems to me more probable that they 

 are appendages of the head, homologous to the palps of the Polynoidae or 

 Nereidae. These structures are shown in side-view in fig. 15d. The mouth 

 appears on the ventral surface as a transverse slit, guarded behind by a 

 crenulate lower lip. All the cirri of the body are tipped with palpocils. 



The ventral cirrus of the first setigerous foot is slender and elongate as 

 in Pisione ; but the dorsal cirrus of the second foot is normally shaped, whilst 

 that of Pisione is long and slender. 



The fifth foot is shown in fig. 15 I. The setigerous lobe is elongate, with 

 two lobes or papillae at the tip. The dorsal and ventral cirri are spherical, 

 attached by narrow bases, and with terminal papillae carrying palpocils. 

 There are two spines with curved tips, the upper one representing the reduced 

 dorsal division of the foot. There are five setae, four of which are compound, 

 whilst the upper one is simple. The compound setae (fig. 15g, a) have 

 slightly curved shafts, which are deeply bifid at the tip, and carry a lateral 

 projection for the articulation of the terminal piece. The latter is short and 

 simply pointed, with a row of fine teeth. The dorsal simple seta (fig. 15g, b), 

 which is present in all the feet, is thicker than the compound setae. It is 

 expanded and bevelled at the tip, where it has a row of spines. Further 

 behind, in the 10th, 11th, or 12th foot, a second simple seta appears beneath 

 the dorsal one, from which it differs in having a smooth tip (fig. 15h). In 

 the posterior segments the number of setae is reduced to four, and they are 

 shorter and thicker than those on the anterior feet. The dorsal simple seta 

 (fig. 15k, a) has lost its spines on the tip, whilst the second simple seta 

 (fig. 15k, b) has a smooth, tapering tip, with no trace of expansion. 



The eversible proboscis (figs. 15a, 15f) carries 14 conical papillae. The 

 two lateral papillae on each side carry in addition a small papilla on their 

 outer margins. Behind the papillae are the jaws. They are of a deep amber 

 colour at the tip. Each jaw is crescent-shaped, with irregular projections, 

 which vary in shape in different individuals. 



Behind the jaws in a muscular stomach, which occupies 3-4 segments. 



Females with immature ova were found in May. 



This species is undoubtedly very closely related to the genus Pisione. 

 Apart, however, from numerous minor differences, such as size, shape of the 

 feet and setae, and relative proportions of the anterior appendages, there are 

 a number of characters which justify the generic separation of this species 

 from the two forms described by Ehlers. In the first place, the head is 

 greatly reduced, and is apparently represented only by the four-sided 

 prominence just behind the anterior dorsal end of the body. The eyes have 



