380 W. C. M'lNTOSH ON BEITISH ANNELIDA. 



are situated at the posterior border, and the anterior toward the front, of the cephalic 

 prominence, but not so far forward as in H. sihhaldii. The tentacle is short, not much, 

 if any, enlarged below the filiform tip, and furnished with a few clavate papillae. The 

 antennae are short, enlarged at the base, and taper at the tip (after the manner of the 

 ventral cirri), and with sparse but distinct clavate papillae. The palpi are gently tapering 

 from base to apex, and have minute papillae under a high power (they are smooth or 

 only wrinkled under a low power). The tentacular cirri taper from base to apex, have 

 no enlargement below the latter, and, similarly to the antennae, are supplied with 

 clavate papillcR. The cephalic appendages are rather short. The dorsal cirri resemble 

 the latter ; and their tips reach anteriorly to the extremity of the ventral bristles. The 

 ventral cirri are enlarged at the base, and have a few clavate papillae. 



There are fourteen pairs of scales, smooth under a lens, but showing sparsely dis- 

 tributed clavate papillae along the posterior border, and over the usual area, under a 

 high power. The first pair are small and round, the size increasing posteriorly till the 

 twelfth, when a diminution again occurs in the thirteenth and fourteenth. Most are 

 rather ovoid than reniform. 



The dorsal bristles are divergent, stout, sharp-pointed, and extremely brittle. A 

 lateral view of a large specimen is given in PI. LXIX. fig. 1. There is a slight bend at 

 the tip, as well as a marked curve in the shaft. A front view of another is exhibited 

 in PI. LXVIII. fig. 4. The ventral bristles have superiorly a short spinous region and 

 a long bifid tip (PI. LXVIII. fig. 5). The tips diminish as usual toward the ventral 

 edge of the fascicle, a few of the lowest having no distinct secondary process at the 

 termination. 



Contrasted with the young of Ilarmothoe imhricata, the head of this form is much 

 more elongated antero-posteriorly ; and the foiu- eyes are visible from the dorsum, 

 whereas in //. imhricata the posterior pair only are generally seen. The tentacle, 

 antennae, and other cephalic processes are difi'erent. The bristles are much larger in 

 H. imhricata, so as to give a difi'erent outline ; and their structure and the scales are 

 essentially at variance. From the Parvienis Ijungmani of Malmgren it diff'ers in the 

 number of the scales, their colour, the structure and size of the dorsal bristles. Its 

 nearest ally seems to be H. sihhaldii. The Polyno'e vasculosa of M. Claparede' likewise 

 approaches it. 



PoLYNOE PLOCCOSA, Sav. This species seems to be in want of careful revision, since it 

 is doubtful if M. de Quatrefages, unless he had (Savigny's specimen, would be able to 

 decide with accuracy what the older author meant. It is the Ilarmothoe sarniensis of 

 Prof. E. Ray Lankester", and abounds all round oiu- coasts, from Shetland to the Channel 

 Islands. It is distinguished from //. imhricata by the general colour of the dorsum, 



' Annel. Che'top. du Golfe de Naples, Suppk'ment, p. 12, pi. i. f. 4. 

 ^ Trans. Linn. Soc. vol. xxv. p. 374, tab. 51. f. 14, &o. 



