108 
THE VOYAGE OF H.M.S. CHALLENGER 
The proboscis ends in a prominent puckered os which projects into the commence- 
ment of the capacious glandular intestine in the ordinary state of the parts. The latter 
canal contains in many cases elongated firm greyish masses of mud with sponge-spicules, 
Diatoms, fragments of Crustacean cuticle, and other debris. 
The same whitish parasitic structure is found in this form as described in Nycliia 
cirrosa from Holsteinborg.^ 
The excellent condition of the specimens procured in the Challenger Expedition 
enables a more perfect estimate to be formed of the structure and relations of this form. 
It evidently differs from any species described by Kinberg. The structure of the head, 
scales, bristles, and the frequent presence of the long median caudal cirrus, are charac- 
teristic, It is true Malmgren attributes a median caudal style to Polynoe scolopendrina, 
Sav., but such is of little moment so far as this well-known form is concerned, for it 
has two short caudal styles, as usual in the group. The head agrees somewhat closely 
with that in the species last mentioned. The occurrence of a single median caudal style 
is a peculiarity in certain examjDles ; others show a pair, and one or two a larger and a 
smaller. The nearest of the three species described by Kinberg from the Strait of 
Magellan is TPermadion magalhcensi, which closely resembles the j>resent form in regard 
to the structure of the ventral bristles, and there may be some ambiguity in his remark 
that the dorsal bristles and cirri are smooth. The coarsely granular scales and the 
divergent dorsal and ventral bristles readily distinguish his Hermadion longicirratus, 
just as the bifid ventral bristles separate his Polynoe antarctica. In the British 
Museum are numerous specimens which had been referred by Dr. Bamd to Kinberg’s 
species, as I also did formerly. The localities have been indicated by Dr. Baird. The 
latter author’s Hermadion ferox appears to be one of the Palmyracese allied to his 
Hermione chrysocoma. 
Polynoe, Savigny, 
Polynoe [Langerhansia) euplectellce, n. sp. (PL XV. fig. 6 ; PI. XIX, fig. 7 ; PL IXa. 
figs. 8, 9), 
Habitat. — Dredged in Euplectella at Station 209 (off the Philippines), January 22, 
1875 ; lat. 10° 14' X., long. 123° 54' E. ; depth, 95 fathoms ; bottom temperature 71°’0, 
surface temperature 81°'0; blue mud. Various remarkable Sponges, Gephyreans, and 
Molluscs occurred on the same ground. 
The species is very fragile and translucent, apparently not well adapted for other 
than commensalistic life. Its length is about 21 mm. and breadth 7 mm. 
The body is long, narrow, and flattened, slightly tapered in front of the anterior third, 
and more so posteriorly. It is pale throughout. 
1 Proc. Roy. Soc. Land., vol. xxv. p. 216, 1877. 
