254 
THE VOYAGE OF H.M.S. CHALLENGER. 
wedge-shaped, the smaller terminating in a somewhat blunt tooth, the larger in a sharper 
tooth, and outside this is a ridge continued into a small accessory plate. The ventral 
surface of the dentary region of the mandibles (Fig. 21) is crescentic, with very distinct 
blackish lines from the pigment-patch at the outer edge of each. A large tooth exists 
on each side of the middle line anteriorly, besides a minute denticulation or two inside 
the pigment-patch. 
The shape of the soft parts of the feet much resembles that in Lmnbriconereis fragilis, 
but the bristles are considerably longer. At the tenth foot there is little difference 
between the outline of the parts and that in Lmnbriconereis elilersii, from the “ Valorous” 
dredgings. The bristles are also similar, consisting of superior winged bristles of 
moderate length, and of inferior winged hooks with long tips. 
At the thirtieth foot, however, the present species has much longer liristles than the 
other ; but a comparison of the hooks is not attainable, since all had been removed from 
the American form. 
In the posterior region a decided divergence occurs in the shape of the foot, which is 
Fig. 20. — Maxillaa and dental plates of Lumhriconereis ehlersii, from the dorsal aspect ; x 15 diameters. 
Fig. 21. — Dental plates of Lumhriconereis ehlersii, from the ventral surface ; X 15 diameters. 
Fig. 22. — Mandibles of Lumbriconereis ehlersii, from the ventral aspect; x 15 diameters. 
more pointed in the present form. The hooks (PL XVIII a. fig. 12) have a shorter wing 
and a more pronounced curve at the neck. 
In transverse section the body- wall shows a thick hypodermic coat, and a strong 
circular layer beneath. The pedicle of the nerve-area is somewhat broad, and the neural 
canal large. Traces of a minute canal are visible in some preparations below the fore- 
going. The alimentary tract has anteriorly very conspicuous longitudinal folds or ridges. 
This appears to be a variety of the European species which I have called 
Lumbriconereis ehlersii, and which was also found during the “Valorous ” Expedition on 
the shores of Greenland. 
