38 PECTINAKIA BELGICA. 



1. Peotinarta brlgica, Pallas, 1766. Plate CXVIII, figs. 4 and 4a — body and tube; 

 Plate CXXXV, figs. 1—1 c— bristles and hook. 



Specific Characters. — Paleolse from ten to fifteen, large, flattened and tapered to a fine 

 point ; a large corrugated firm surface of the crown above them, the margin of which is 

 deep and smooth, curves ventrally a little within the edge of the paleolas, and ends at the 

 long anterior cirrus. Two eyes over the brain. Veil (tentacle-membrane) restricted in 

 area, fan-shaped, and with ten to eleven (seventeen, Lo Bianco) large tapering papillae in 

 front, and a few others on the lateral edges as they pass to the mouth (in all about twenty- 

 five). The tentacles are fixed to its posterior border — which is smooth. Body about 

 70 mm. with the scapha in addition. Second cirrus arises a little behind the rim of the 

 crown, and this segment with the two branchial segments makes a region of three; the first 

 branchial segment has an incomplete glandular ridge ventrally, whilst that of the second is 

 complete. Third segment with two ventral lobes (Hessle). Seventeen bristled segments 

 anteriorly ; thirteen with hooks, each with seven to eight teeth in profile. Dorsal surface 

 smooth and rounded; ventral with glandular areas and ridges in front; flattened and 

 grooved posteriorly. The next region consists of three bristled segments but hooks are 

 absent. The first two have glandular ridges ventrally, whilst the third approaches the con- 

 dition in the succeeding segments. The third region has fourteen bristled segments and 

 prominent lamella for the rows of hooks, the largest lamella being in front. Bristles of 

 two kinds — simple, stout, tapering forms, with finely-tapered tips having traces of wings, 

 and those with a spear-head dilatation distally, a serrated edge, and long tapering hair- 

 like tips. Hooks commence on the thirteenth segment, with seven to eight recurved 

 teeth beneath the crown, then a group with minute serrations, and lastly the sinuous 

 prow : the shaft is short. Two cement-glands. Caudal process tortoise- shaped, of five 

 segments, bent at more than a right angle to the dorsum ; dorsal surface flattened, with 

 a median keel or process and symmetrically arranged transverse ridges ; rim little 

 elevated; two notches beyond the hooks and occasionally a minute papilja or two. 

 Caudal hooks (six to twelve ?) have stout straight shafts tapering toward the neck, 

 which first bends a little backward, then gently forward to a strong point. General 

 colour of the body yellowish-orange in females, whitish in males, and the branchise 

 are reddish-yellow. Tube large, nearly straight, tapered, composed usually of small 

 grains so that the surface is smooth, the separate joints not clearly visible. Often 

 brownish. 



Synonyms. 



1766. Nereis eylindraria, var. belgica, Pallas. Miscell. Zool., p. 122, Tab. ix, figs. 3--13. 



„ Sabella granulata, Linnaeus. Syst. Nat., p. 1268. 



1773. Solen fragilis Spec. 2, Klein. Descr. Tubul. Mur., p. 21, Tab. i, fig. 5. 



1777. Nereis cylindracea belgica, Pennant. Brit. Zool., iv, p. 147. 



„ „ conchilega, idem. Ibid., iv, p. 47. 



„ Sabella tubiformis, idem. Ibid., iv, p. 148, Tab. xcii, fig. 163, and Edit., 1812, iv, p. 372, 



pi. xcv, fig. 2. 



