374 LUMBPICONEREIS FRAGILIS. 



Valentia and in Dingle Bay and other parts on the W. and S.W. coasts of Ireland (J. G. 

 Jeffreys). Procured also in the 'Knight Errant' at Station 3; Connemara (A. G. 

 Moore). Most observers have, from the days of 0. F. Muller, found it on muddy 

 ground. 



Nova Zembla (Theel) ; Siberia and Behrings Strait (Wiren) ; Canada (dredged by 

 Dr. Whiteaves). It seems to be northern, and does not reach the Mediterranean. 



Head forms a smooth conical process with a dimple posteriorly, which leads into two 

 pits (nuchal), into which two small papillae or bosses project from the first segment. 



Body elongate, little diminished anteriorly, but more tapered posteriorly, and ending 

 in four caudal cirri. The first two segments are devoid of feet, and the first is broader 

 than the second. The mouth opens inferiorly behind two massive tips (homologues of 

 palpi ? ) separated by a median fissure. The hind lip is curved and crenate. 



The dental apparatus (Plate LXII, fig. 1) presents a pair of boldly curved maxillse, 

 the base being continued posteriorly into a spear-shaped process, and each of the great 

 dental plates has four teeth. The inner antero-lateral plate has a prominent tooth 

 internally and so has the outer in most cases. A horny patch occurs behind these and fits 

 against the teeth, and internally a horny bar passes toward the great dental plate. From 

 the ventral surface the broad lamina of the great dental plate has a similar pale area in 

 front, so that the surface is boldly chequered. The mandibles (Plate LXII, fig. 1 a) are 

 anchylosed, and have dense, whitish calcareous edges. The fine brown lines run from 

 side to side continuously. The appearances are somewhat the same as in L. Pettigrewi of 

 the ' Challenger.' 



In this form the nerve-cords in section (Fig. 77) often show a symmetrical arrange- 

 ment of the neuroglia, the median band passing upward, splitting and surrounding the 

 great dorsal neural canal, which has coagulable contents. The pedicle is shorter than in 

 some species. Additional smaller neural canals occur below the larger, but whether this 

 is due to branches or to the methods of preparation is uncertain. 



The first foot has a considerable tongue-shaped lobe (Plate LXXIII, fig. 8) projecting 

 posteriorly, five black spines, and only simple somewhat short winged bristles of the same 

 type, such as exist on the feet behind it. These bristles form two groups, an upper 

 series of longer, and a ventral series of shorter forms with slightly broader wings. The 

 following feet to the twentieth retain this structure except that the posterior lobe 

 becomes a little longer. The anterior lobe is bluntly rounded in lateral view, whilst the 

 posterior has a nearly horizontal dorsal border, a bluntly conical point, and then, after 

 fusing with the inferior edge of the anterior lobe, the outline trends inward and backward 

 with a long curve to the body. The space between the two lobes is greater in the 

 anterior than in the posterior feet, thus affording room for the larger setigerous process 

 anteriorly. Posteriorly, and especially toward the tail, the feet considerably increase in 

 length, and the posterior lobe becomes pointed. 



At the tenth foot two groups occur, a dorsal of strong curved bristles with the wings 

 on the convex or inferior edge and a comparatively short tapering tip, and a more 

 numerous lower group with less elongated tips, the edge of the wings often uppermost. 

 The foot is supported by five spines, pale at the base, black throughout the rest of their 

 extent. This structure occurs in the succeeding feet as far as the twentieth, the only 



