402 NOTOCIRRUS SCOTICUS. 



The first two segments are scarcely so broad as the succeeding, and with the following 

 six or seven are more rounded (as in Lumbriconereis) than those behind, which present a 

 deeper sulcus at the segment-junction. Behind the thirtieth foot the body becomes 

 moniliform, the lateral body- wall projecting outward like a cone with the foot at the tip. 

 The anterior segments, moreover, have longer bristles, and the tips of these are more 

 finely tapered than in the region behind. 



Only one example had a tail, and that had recently been regenerated. No distinct 

 papillae occurred at the tip, though the minute size of the part and the absence of feet on 

 the segments showed that it was only in process of growth. 



Proboscis. — In Notocirrus, as in Cirrobranchia, Ehlers, a considerable modification of 

 the dental apparatus has occurred (Plate LXII, fig. 9 a). The maxillae are no longer 

 prominent and might easily be overlooked. They form small toothed processes in the 

 usual position, with two to four curved fangs and an enlarged base, the thicker edge of 

 which touches the enlarged anterior ends of the posterior appendages. Some would 

 consider them merely continuations of the series of dental plates which lies in front of them, 

 but in all probabitity the foregoing is the more satisfactory interpretation, unless it is to 

 be supposed that the maxillas are entirely absent. The posterior appendages have an 

 enlargement at the articulation, and a spur a short distance downward, and then form 

 two long tapering processes. In front of the maxilla? are three dental plates. The posterior 

 is the largest, and has a dark blackish-brown colour, with several large teeth in front, 

 and an inner long process, which passes backward to the base of the maxillae, bearing 

 smaller recurved teeth. Externally about the anterior hook of the maxillae it has a well 

 marked process or shoulder. The plate in front also has a posterior process or shoulder, 

 and six or seven teeth on its inner edge. The anterior plate is still smaller and shows six 

 well marked teeth. Each of these plates is supported by a thin plate, which passes 

 inward and ventrally. 



The mandibles (Plate LXII, fig. 9 b) form two dark brown processes with a crenate 

 anterior edge which is slightly bevelled. Behind is a constriction externally, the outline 

 curving outward again and then inward to the slightly tapered posterior end. The two 

 limbs (that is, the posterior processes) enclose a wedge-shaped space between them, and the 

 edge along which they touch in front is nearly straight. It is marked by a slight shoulder 

 posteriorly. 



The typical foot (Plate LXXIV, fig. 6) has a small dorsal lobe (cirrus P) in which is 

 a single vascular loop. The setigerous region beneath is supported by a pair of strong 

 spines, the points of which often project beyond the surface. The bristles (Plate 

 LXXXIII, fig. 3) are very brittle, and have comparatively short tips with wings, 

 which are broad and boldly serrated at the edges throughout the greater part of their 

 length. Foreign particles thus adhere very readily to them and obscure their structure. 

 A small lobe or papilla (Plate LXXIV, fig. 6 a) also exists ventrally, so that the conical 

 foot has two, a dorsal and a ventral, as in Arabella tricolor. 



The Gordius piisilliis of Delle Chiaje l would seem to refer to this or a very closely 

 allied species. 



1 < Mem./ iv, pp. 177, 19G ; Tav lxiv, figs. 8 and 9, 1829 ; and ' Descriz./ iii, p. 82; v, p. 97, 1841. 



