HYALINCECIA TUBICOLA. 419 



of those of Eunice, occur (Plate LXXXIV, figs. 7 and 7 a). The end of the shaft is 

 slightly dilated and the bevelled region has spikes. The moderately elongated distal 

 piece is sloped at the base and bifid at the tip, both the terminal and the secondary 

 processes being prominent, and they are guarded by wings. The bristles (Plate 

 LXXXIV, figs. 7 b and 7 c) are slender and have very narrow wings, whereas in the fully 

 developed forms of the two species above mentioned they have the shape of Valentin's 

 knife. 



Posteriorly the jointed hooks are supplanted by two simple forms which resemble 

 those so frequently found in Eunice, wings being present in the perfect examples, but 

 they are sometimes abraded. The bristles are also shorter and some are characteristically 

 curved at the point. None of the brush-shaped bristles were observed. The hooks in 

 the posterior region (Plate LXXXIV, fig. 7 d) have a powerful main fang and a smaller 

 one on the crown. 



This species inhabits a tube (Plate LXIV, fig. 4 c) composed of secretion strengthened 

 by gravel and shell-fragments, yet De Quatrefages thought that its tube resembled that 

 of Hyalinoecia tubicola. 



Ehlers (1868) confused this species with Hyalinoecia tubicola, from which it differs in. 

 essential features, such as the arrangement of the branchiae, the presence of eyes, the 

 structure of the bristles, and the pigment. 



Dr. Baird (1870) described this form as new under the name of Hyalinoecia Ulineata, 

 his examples having been dredged off the coast of Cornwall. He noticed that it had a 

 pellucid, soft tube of a thin horny texture, but he does not allude to any extraneous 

 materials. 



Grube (1878) considered De Quatrefage's species as identical with Hyalinoecia 

 tubicola. 



2. Hyalincecia tubicola, 0. F. Mutter, 1788. Plate LIV, figs. 5, 5 a — head, and 5 b— teeth ; 

 Plate LXIV, figs. 5-5 b— head, teeth, tube; Plate LXV, fig. 15— mouth; Plate 

 LXXV, fig. 11— foot; Plate LXXXIV, figs. 8-8 d— bristles.' 



Specific Characters. — Head typical, the tentacles arising from ringed bases, and being 

 long and smooth. No eyes. The frontal lobes (palps, Pruvot; tentacles, Grube) are ovate. 

 The palpi form two bulbous pads separated by a median furrow ventrally. Body long, of 

 about eighty-five bristled segments, pale brownish, iridescent, with the double red line along 

 the dorsum, and the bright red double line in each branchia. The first segment is narrower 

 than the succeeding. The second segment is considerably broader and carries the first 

 feet, which are large, slope forward, and have a disk-like process at the tip. No tentacular 

 cirri. The falcate bristles are strongly hooked at the tip, and beneath is a prominent 

 secondary process resembling that in Onujohis britannica, and winged. At the sixth and 

 seventh feet the ventral cirrus is pad-like. Proboscis with maxillae enlarged posteriorly 

 so as to leave a short hooked anterior region. Posterior appendages bluntly conical in 

 outline. A dark brown border between these runs forward to a transverse bar between 

 them and the maxillae. Eight great dental plate with thirteen teeth ; left with thirteen 

 (sixteen, Ehlers). Left anterior curved plate with seven teeth; right with eight. 

 Mandibles with a slightly denticulated edge anteriorly and long tapering shafts. 



