132 POLYMNIA NEBULOSA. 



in valves of Pecten operculars (W. C. M.). Dredged off the Hebrides in considerable 

 numbers ; 9 miles off Balta (J. G. J.) ; Valentia Harbour in 2 fathoms amongst soft 

 mud (J. G-. Jeffreys and A. C. Haddon) ; Torquay (Blwes) ; Plymouth (Spence Bate 

 B. Bowe and Crawshay) ; Blacksod and Clew Bays, etc. (Southern). 



It is elsewhere found in the Mediterranean (Delle Chiaje, Milne- Edwards, Grube 

 da Costa, Panceri, Claparede, Fauvel) ; Adriatic (Grube), amongst stones and nullipores 

 as well as in a brown sponge ; shores of France (Milne-Edwards, Grube, De St. Joseph) • 

 Azores and Gibraltar, Isles of Gambia (Fauvel) ; Finmark (Norman) ; North Sea; Gulf of 

 St. Vincent, Australia (Fauvel). 



The cephalic region is distinguished by the great size of the upper collar or arch, 

 and by its frilled inward curve at each lower edge. Its upper surface is somewhat 

 flattened, that is to say, only a shallow groove is present, the mass of tentacles springing 

 from the posterior half near the rim. These tentacles are pale orange in life, and snotted 

 with white so as to give them a barred appearance, and their movements are remarkable, 

 for not only do they aid in the construction of the tube, but hoist the animals up the 

 perpendicular side of a glass vessel or in any direction, and are continually mo vino- as a 

 series of complex threads. All are deeply grooved. When the annelid is hidden amongst 

 shells and tufts of Geramium the long spreading tentacles resemble independent Nemerteans, 

 and in large examples stretch nearly a foot from the body. Below the mouth is a 

 transversely elongated fold, and then follows the broad lower lip, which ceases at the 

 dorsal fold on each side. 



Behind the dorsal collar are a large number of dark pigment-spots — the so-called eyes. 

 These are generally concealed by the posterior fold of the collar. In a small variety met 

 with under stones between tide-marks at St. Peter Port, Guernsey, they are both 

 numerous and distinct, and, moreover, remain in spirit. They form in a large Irish 

 example a conspicuous brown band below the collar. 



Body 9 — 1 inches or more in length, and as thick as the little finger behind the 

 bristles, soft and mobile, with numerous (sixty to ninety) narrow segments, the anterior 

 region being enlarged, and the posterior tapered to a comparatively large terminal anus 

 with a crenate margin. Though the dorsum as a rule is convex, the preparations are 

 generally marked by a slight median groove anteriorly. Ventrally, a deep median groove 

 runs from one end to the other. In large examples the swollen anterior end is tessellated, 

 whilst in the smaller posterior region this is less evident. 



Each segment consists of two rings, one at the bristle-tuft and one in front of it 

 dorsally, and these are continued ventrally, the groove in the ridge for the hooks being 

 opposite the bristle-tuft, and only a narrow space occurring between them (the ridges). 

 Posteriorly the segments are more definitely marked, the broader division containing the 

 lamella for the hooks, a narrow ring being in front of it. Then the two rings are only 

 indicated laterally above the lamellae for the hooks, and finally for some distance at the 

 tail each segment is undivided, and moreover, the segments become more and more 

 minute as they approach the last, which is broader than those in front of it and has 

 a minutely crenate margin. The ventral surface in this region is considerably diminished 

 whilst the dorsal arch is increased. The ventral glandular shields are narrow and long 

 in front, broader and shorter from side to side from the fifth backward, and they often 



