POLYXOE SCOLOPEXDPINA. 389 



large female, again, was laden with fairly advanced ova in July in Herm, so that the 

 period of deposition could not be distant, probably in autumn. They were somewhat 

 less advanced in a large female during the same month in Shetland, no free ova occurring 

 in either case. In August the condition of the ova was very similar to the last (e. g. in 

 one sent from Arran by Dr. Howden). Sir J. Dalyell, again, found that in the middle of 

 July a large specimen produced in confinement about 10,000 eggs, the mass having a 

 reddish hue as it lay on the bottom of the vessel. De St. -Joseph found ripe specimens 

 with the ova and sperms within a membrane, as shown by Claparede in Hermadion 

 fragile, but he omits to mention the date. 



De Quatrefages adds nothing new to the account of the species. Grrube found that 

 this author's Polynoe foliosa in the museum at Paris agreed with the present species, as 

 Malmgren had hinted. 



Ehlers gives a somewhat detailed description of the small specimen (13*5 mm.) from 

 the ' Porcupine. 5 



Genus XX. — Polynoe, Savigny, 1820. 



Head elongated antero-posteriorly, with a somewhat indistinct peak on each side, 

 beneath which is the lateral tentacle. Anterior and posterior eyes widely separated. 

 Palpi with dense rows of clavate papillae. Body linear-elongate, with many segments 

 (over 100). Segmental papilla long. Scales fifteen pairs, with a broad belt of papillae 

 on the surface anteriorly. Dorsal division of the foot minute, with small spinous bristles 

 truncated at the tip. Ventral division has a single strong hastate bristle superiorly, and, 

 below, strong bifid bristles with short spinous regions. 



The median area for the nerve-cords is comparatively wide, the oblique muscles 

 having a broad attachment to its exterior border. A firm membrane bounds the area 

 internally, and a symmetrical longitudinal muscle runs above it on each side of the 

 median line. 



Commensalistic. 



Polynoe scolopendeina, Savigny, 1820. Plate XXV, f[g. 7. 



Specific Characters. — Head pinkish, with the long diameter antero-posterior ; a 

 somewhat indistinct peak on each side. A pair of distinct eyes in front of the nuchal 

 collar, and a larger pair with lenses, scarcely visible from the dorsum, near the anterior 

 part of the peak, and directed forward and slightly outward. Median tentacle larger 

 than the palpi in spirit, with a slight enlargement below the filiform tip, and densely 

 clothed with short clavate cilia having truncated tips. Lateral tentacles of moderate 

 length. Palpi have dense rows of minute clavate papillae. Body linear-elongate, 2 to 5 

 inches long, bristled segments from 80 to over 100, reddish brown, or brown on the 

 dorsum, the pigment being arranged in various touches and bars. The posterior ventral 

 region has also brown bars and touches, especially on the segmental eminences. The 



