384 



LUMBBICONEREIS HIBERNICA. 



the scissor-like action of the great dental plates, aided by the chisel-like effect of the 

 mandibles, which would not only sever pieces held by the maxillae, but would also press 

 them against the great dental plates. The muscles attached to all these parts are powerful. 

 The action of the parts when inverted would not be very different. When the proboscis 

 is thus thrust out, the head is bent up at an angle, and in semi-extrusion the same 

 tendency is noticed. 



The neural canal is small and indistinct, and situated in an upper median segment of 

 the ovoid area in transverse section. The area is surrounded by a dense series of nuclei. 

 The oblique muscles are attached to the upper and outer edges of the area, The 

 hypoderm is comparatively thick and the pedicle long. 



The first foot has a small triangular posterior lobe and two groups of tapering 

 winged bristles. One in the centre has a somewhat short tip, and thus may indicate the 

 condition in the following feet, The spines are pale and three or four in number, and 



Fig. 79. — Transverse section of the body-wall of Liimbriconereis hibernica. 



thus the form is readily discriminated from the allied species L. vm^atiems. The second 

 foot has five pale spines. 



The tenth foot has four pale spines and a short conical posterior lobe, and a shorter 

 curved anterior lip. Dprsally is a group of tapering winged bristles (Plate LXXXII, 

 fig. 5), with curved and finely attenuate tips. Below the spines is a group of character- 

 istically tapered simple hooks (Plate LXXXII, fig. 5 a), which indicate how easily such 

 forms could merge into a tapering bristle. The terminal hook is minute, with a series of 

 coronal serrations. When viewed antero-posteriorly, the double frill of the wings is 

 observed at the tip (Plate LXXXII, fig. 5 /;). Below are one or two tapering winged 

 bristles. 



The tips of the simple winged hooks gradually shorten, so that at the twentieth foot 

 they are proportionally about half the length. The tapering bristles above and below 

 them are similar to those in front. There are four pale spines. 



At the thirtieth foot the lobes (anterior and posterior) are more nearly equal, and 

 there are four pale spines. The second or inferior group of dorsal bristles has finely 

 tapered and very long tips, as in certain allied species, and the hooks (below the spines) 

 have now short tips with broader wings (Plate LXXXII, fig. 5 c) and long shafts. The 



