SYLLIS CUCULLATA. 191 



The feet (Plate LXX, fig. 15) bearing the long swimming-bristles (Plate LXXIX, 

 fig. 9) have the region between the cirrus and the setigerous lobe more prominent, and 

 the strong translucent and long bristles piercing a central eminence supported by a spine 

 of a more slender type than those of the inferior lobe. These long bristles are beautifully 

 iridescent. The conical setigerous lobe follows, its strong spine piercing the tip above the 

 bristles, which have the hooks of the terminal piece directed upward (as usual). The 

 ventral lobe agrees with that in front. 



This is probably the Nereis scolojpendroides of Montagu (MS. Drawings, Linn. Soc, 

 Plate XXXVIII, fig. 1, 1808). 



De Quatrefages treated this form as pertaining to a special genus. 



An Ioida (Plate LIX, figs. 16 and 16 a) procured at Plymouth by Dr. Allen in 

 September, appears to differs from any procured in the north, and probably pertains to 

 a southern species. 



The head is deeply bilobed and furnished with two very large, somewhat ovoid eyes 

 on each side. The foot shows a crenate dorsal cirrus of considerable length. Swimming- 

 bristles occur dorsally. The setigerous region bears a series of bristles, but as the 

 specimen was lost, their structure is unknown. The tail has no median process. The 

 softness of the crenated cirri would suggest a connection with Pionosyllis prolifera or 

 a nearly related form. 



The genus GhdetosyUis of Malmgren (1867) refers to a nearly allied, though probably 

 different, sexual form distinguished by the great length of the tip of the falcate bristles. 



The Tetraglene rosea of Grube, 1 from the Adriatic, is apparently the loida-stage of 

 a Syllis, having a moderately long slender tip to the compound bristles. Small simple 

 bristles occur in the dorsal division, and long swimming-bristles of the typical form are 

 found in the ventral division of the foot. 



2. Syllis cucullata, n.s. Plate LX, fig. 3 — head; Plate LXX, fig. 17 — foot; Plate 



LXXIX, ^g. 11— bristle. 



Specific Characters. — A somewhat massive species, with four rather large eyes nearly 

 in a square. Palpi of considerable size. Tentacles and tentacular cirri of moderate length 

 and crenated — especially towards the tip. Foot with a bluntly-conical setigerous region 

 and two hooked spines. Bristles rather stout, translucent, dilated and bluntly bevelled 

 at the end of the shaft, and furnished with spines. Terminal piece short, simply and 

 boldly hooked. 



Habitat. — Under stones between tide-marks, Luccomb Chine, Isle of Wight. 



Head (Plate LX, fig. 3) rounded, with two considerable palpi in front. Eyes 

 moderately large, the anterior pair only very slightly the wider apart, so that they nearly 

 form a square. Tentacles and tentacular cirri of moderate length — slightly moniliform. 



Body comparatively firm and broad, little tapered anteriorly, but diminishing to a 

 slender tail posteriorly. Proboscis exserted. 



1 < Arch. f. Xaturges./ Bd. xxix, p. 42, Taf. iv, fig. 6 (1863). 



