REPORT ON THE ANNELIDA. 
4G7 
selective power, however, must have been exercised, for the alimentary canal contained 
greyish mud in which small GlohigerinoB and other Foraminifera, an occasional sponge- 
spicule, and numerous Coccoliths were found. 
The body-wall presents a largely developed hypoderm, that along the ventral arch 
being especially massive. The nerve-cords are comparatively large, elongated from 
above downward, so as to present the aspect of an olive, or together of a double cocoa- 
nut. They are placed outside the circular muscular coat, which is moderately developed. 
The longitudinal dorsal muscles are somewhat less extended than usual in the group, 
and are thin. The attachment of the fibres suspending the alimentary canal alone 
disconnect them. The longitudinal ventral, on the other hand, are proportionally 
extended as well as massive, and the hiatus between them is moderate. The oblique 
are moderately developed, and are fixed to the circular just outside the nerve-area. 
The anterior glands and perivisceral corpuscles occur in the body-cavity. 
The type differs from any known form in regard to the structure and arrangement 
of the branchiae (which appear to be diagnostic). The hooks, however, have certain 
relations with Theleims, but differ from the known genera in the direction of the mucro. 
The number of the bristle-bundles is the same as in Pkenacia, De Quatrefages, viz., 
twenty pairs. 
Euthelepus chilensis, n. sp. (PI. LI. figs. 4, 5 ; PI. XXVIIIa. figs. 14, 15). 
Habitat . — Trawled at Station 299 (off Valparaiso), December 14, 1875; lat. 33° 3P S., 
long. 74° 43' W.; depth, 2160 fathoms; bottom temperature 35°'2, surface temperature 
62°‘0 ; sea-bottom, blue mud. 
The longest fragment measures about 35 mm., with a diameter anteriorly of 2 '5 mm. 
As usual the tough lining of the tube has prevented early percolation of the spirit, so 
that the greater part of the animal is pulpy. 
This is another example of the remarkable type observed in Euthelepus setuhalensis, 
and apparently intermediate between the Ampharetidae and the present family. 
Anteriorly are a number of large crenate tentacles, longest dorsally and diminish- 
ing on each side ventrally. The latter form a fan- shaped series in the jmepara- 
tion, probably partly due to the effect of compression (the animals having been 
preserved in their tubes). The dorsal tentacles are very long and thick, extending in 
the specimens to the seventh or eighth bristled segment. Moreover, they are not 
marked by grooves, though some of the short ventral forms show a basal furrow. They 
arise as in Thelepus from the truncated cephalic region, and completely occupy the 
lobe all round. The buccal segment bears no processes. The next segment (the first 
bristled) has at its anterior border a pair of long smooth subulate branchiae, winch taper 
