244 
THE VOYAGE OF H.M.S. CHALLENGER. 
May 12, 1875; lat. 35° 11' N., long. 139° 28' E.; depth, 345 fathoms; bottom 
temperature 41°‘l, surface temperature 64°’2 ; sea-bottom, green mud. 
This species is considerably larger than the foregoing, resembling in bulk 
Lumbriconereis capensis. The total length of the fragments is about 140 mm., and the 
breadth of the widest region (anterior third) about 7 mm. 
The body has the usual shape, being slightly tapered in front, and gradually 
diminished from the anterior third backward to the tail, which ends in four styles, two 
longer situated dorsally, and two shorter ventrally. 
In this species the head (PL XXXVI. fig. 13) is thicker and less acute than in the 
previous forms, agreeing in this respect with certain British examples of the group. The 
Fig. 9. — Lateral view of the maxill® and dental plates of Lumbriconereis japonica ; x 15 diameters. 
Fig. 10. — Maxillae and dental plates of Lumbriconereis japonica ; x 15 diameters. 
Fig. 11. — Mandibles of Lumbriconereis japonica, from the ventral surface ; x 15 diameters. 
snout, both dorsally and ventrally, is devoid of longitudinal lines. The oral region has 
three folds on each side, the “ boss ” in front and superiorly, and two beneath. The 
crenations on the margin appear to be less numerous than in Lumbriconereis fragilis, 
only three in the middle running backward to the posterior border of the posterior buccal 
segment. 
When viewed laterally (Fig. 9) the maxillae show the double curvature (anteriorly 
and posteriorly) even more distinctly than in Lumbriconereis bifurcata. In certain 
positions (as in the preparation) the serratures of the great dental plates stand pro- 
minently above the level of the maxillae. The posterior spathulate processes (Fig. 10) 
