482 
THE VOYAGE OF H.M.S. CHALLENGER. 
A small example, measuring 18 mm. in length, and having a diameter of 1'2 mm. 
anteriorly. 
There is little in external appearance to distinguish it from the common species, 
and the softened condition of the cephalic region renders any remarks on the cutaneous 
folds somewhat uncertain. No divergence is apparent in regard to the branchiae. Very 
few bristles remain, but, so far as observed, no diagnostic feature is noticeable in their 
structure. The anterior hooks (PL XXIXa. fig. 12) have rather a large crown, and the 
series of teeth above the great fang is unusually developed, the points projecting forward 
over the base of the latter, so as to resemble in this respect the specimens from Station 47. 
The posterior hooks, again (PI. XXIXa. fig. 13), are furnished with two or three 
teeth above the great fang, but it is doubtful whether that immediately over the latter 
be not one of the duplicate series, for it is encroached on by the bases of the great fang 
below, and the smaller tooth above it. Their minuteness renders the diflferences in the 
outline of the base, and in the sinus below the great fang, less precise as a means of 
diagnosis. 
The fine sandy mud in the intestine showed a few Diatoms and sponge -spicules, but 
organisms were rare. 
The structure of the body -wall is similar to that in the foregoing. 
The relation of this form to Kinberg’s Terebellides sieholdii,^ from Banks Strait, is 
uncertain. There is little that is really diagnostic in the description of the Swedish 
author. 
Terebellides elilersi, n. sp. (PI. LI. fig. 8 ; PI. XXIXa. figs. 9—11). 
Habitat. — Dredged at Station 174 d (a little south of the Fiji group), August 3, 1874 ; 
lat. 19° 5' S., long. 178° 16' E. ; depth, 210 fathoms; surface temperature, 77°*7 ; 
sea-bottom, coral mud. 
The specimen is of average size, measuring about 35 mm. in length, and having an 
anterior diameter of 2 ’2 mm. 
In externa] a23pearance it corresponds with the foregoing forms, except that the 
relative sizes of the anterior and posterior divisions greatly differ. The anterior (or 
external) pair, as in some European examples, are only a little larger than the posterior, 
and they do not send an inferior process downward in front. The whole branchial 
ap 2 >aratus is much smaller than in Terebellides strcemi, and the lamellar processes are 
much diminished. In consequence of this structure the four appendages are borne 
upward in an erect and separate condition. 
The bristles (PI. XXIXa. fig. 9) are somewhat stouter than in the Norwegian species, 
^ Op. cit., 1866, p. 346. 
