320 
THE VOYAGE OF H.M.S. CHALLENGER. 
debris projecting from it, so as to make an irregular margin. Some of the empty 
tubes are quite flaccid. It is curious that what appears to be the lower surface of 
the tube is specially coated by the foraminiferous tests, the long axes of these being 
parallel with that of the tube. The tests are firmly adherent. 
In a large specimen from Station 298 the body- wall is greatly distended by the 
male elements, very large masses of sperm-cells filling up the whole area around the 
alimentary canal except the median dorsal and ventral attachments. The latter consists 
of a strong band of muscular fibres passing downward on each side of the nerve-area to 
the circular coat, and forming a hollow arch over the area, which is comparatively small. 
In an example from Station 299 the body- wall more closely approached the typical 
form, except in the absence of the neural canal. 
Nothria macrobranchiata, n. sp. (PL XLI. figs. 1, 2, 3 ; PL XXIIa. figs. 6, 7). 
Habitat . — A few specimens were dredged at Station 232 (south of Yedo, Japan), May 
12, 1875; lat. 35° 11' N., long. 139° 28' E.; depth, 345 fathoms; bottom temperature 
41°T, surface temperature 64°‘2 ; sea-bottom, green mud. 
When removed from the tube the Annelid measures 78 mm. in length, and at its 
widest part is nearly 6 mm. across the feet. The posterior region, however, seems to be 
Fig. 77. — ^Maxillse and dental plates of Nothria macrobranchiata, n. sp. ; x 24 diameters. 
Fig. 78. — Ventral aspect of the mandibles of the same ; x 24 diameters. 
undergoing regeneration, so that it is probably longer. It is thus much longer in pro- 
portion to its tube than any of the others. 
