376 LUMBRICONEKEIS LATREILLII. 



nereis fragilis by the much more distinctly segmented body, each segment having a 

 greater antero- posterior diameter, and the feet are thus wider apart. The contour of 

 the foot also diverges, yet it is difficult to express the change in words, though the 

 posterior flap is larger in L. fragilis. In addition to the long winged bristles others are 

 peculiarly jointed, for instance, from the first in the tenth foot, and the structure of the 

 posterior hooks also differs, as likewise do the spines which are not black. 



A variety of L. fragilis, from the south west of Ireland, off the Blasquet, has in the 

 tenth foot the middle group of bristles slightly blunted, so as to form a stage in its 

 approach to the foregoing. 



2. Lumbriconekeis Lateeillii, Audouin and Edwards, 1834. Plate LIV, fig. 6; Plate 

 LXXIII, figs. 9 and 9 a— feet ; Plate LXXIV, fig. 12— head ; Plate LXXXII, figs. 

 3-3 c — bristles. 



Specific Characters. — Head a short blunt cone, with a median band attached to the 

 succeeding segment in the centre posteriorly, and at each side of the latter a dimple 

 receiving a process from the first segment. Two papillae in front of the mouth are 

 transversely elongated. Body similar to that of L. fragilis, with four anal cirri. Maxilla? 

 strongly curved and rather short, the basal plates trending to a short posterior lozenge. 

 Great dental plates with four teeth ; each anterolateral with one tooth ; a horny patch 

 in front, and a horny bar outside the anterior half of the maxilla?. Mandibles have 

 spatlmlate anterior ends anchylosed in a wide angle, and two short roots. First foot has 

 three pale spines, a short, bluntly conical posterior flap, winged tapering bristles superiorly 

 and inferiorly, and among the latter one or more winged jointed hooks, the ends of which 

 have four or five spines. Typical foot (as far as seventeenth) has a nearly horizontal 

 edge to the posterior lamella, whilst the ventral edge is long and sinuous. Spines (four) 

 pale. Tapering winged bristles superiorly ; articulated hooks, with the distal end of the 

 shaft slightly curved backward and dilated, and with a narrow wing on each side. End 

 of shaft bevelled to a sharp point, and with a posterior fillet. Terminal piece of consider- 

 able length, diminishing distally, constricted at the neck of the hook, which is small, with 

 several sharp spikes above it. One or two winged bristles occur below the spines at the 

 ventral border of the foot. Behind the foregoing simple winged hooks take the place of 

 the jointed. The foot also has a more abrupt inferior curve, so that its depth is 

 increased. Posterior feet have the posterior lobe prominent, and the hooks have the 

 primary fang large. 



Synonyms. 



1834. Lumbrinereis Latreillii, Aud. and Edw. Annel., p. 168, pi. iii b, f. 13 — 15. 

 1840. Lumbriconereis Nardonw, Grube. Actin. Echin. und Wiirmer, p. 79. 

 1851. „ „ idem. Fam. AnneL, pp. 45 and 124. 



1862. „ tingens, Keferstein. Zeitschr. f. wiss. Zool., Bch xii, p. 102, Taf. ix, f. 1—9. 



1863. „ Eclwardsii, Claparede. Beobacht., p. 58, Taf. xiv, f. 14—22, 



1864. „ ,, Grube. Insel Lussin, p. 79. 

 „ Zy globus Edwardsii, Claparede. Glannres Zoot., p. 114. 



1865. „ „ De Quatrefages. Annel., i, p. 366. 



