518 
THE YOYAGE OF H.M.S. CHALLENGEE. 
without the tube, was procured by the Antarctic Expedition of Sir J. Clark Eoss at 
Narjon Island, and which is still present in the collection of the British Museum. 
The specimen, which was described from the collection made at Kerguelen by the 
Eev. A. E. Eaton during the Transit of Venus Expedition,^ had no operculum, and thus 
it was difficult to say much about it. An examination of the specimen in the British 
Museum, however, removed all doubt as to the relationship. Grube’s species [Serpula 
patagonica), which was obtained both at Kerguelen and in the Strait of Magellan, seems 
to be identical. The Serpula vasifera, Haswell,^ from Port Jackson is a near ally, 
having, however, fewer crenations in the operculum, and a different hook. The 
Serpula juhesii, Baird,® is a distinct species. 
Serpula narconensis, Baird, var. magellanica nov. (PI. LV. fig. 2 ; Ph XXXIa. figs. 
24, 25). 
Habitat . — Trawled at Station 308 (in the Strait of Magellan), January 5, 1876 ; lat. 
50° 8' S., long. 74° 41' W.; depth, 175 fathoms; surface temperature, 51°’7 ; sea- 
bottom, blue mud. 
A much smaller variety than the former, the total length being 23 mm., and the 
diameter anteriorly a little more than 1 mm. 
In the general form of the body it agrees with the foregoing, the thoracic bristle-tufts 
and other parts having the typical arrangement. The brauchim are similar though 
apparently longer, and also possess bare filiform tapering tips. The operculum resembles 
that of Serpula narconensis, but it is easily distinguished, being thinner, and being 
furnished with a longer vase-shaped portion and a longer pedicle. There are thirty- 
four divisions of the rim of the operculum, being only one less than in Serpula narconensis, 
but the tips of the segments in the latter are much more pointed, from the inflection of 
the boundary-line on each side on its way to the apex. In this form the lines are nearly 
straight, as in Serpula vermicularis. The apex of each, however, is less truncated than 
in the latter. 
The bristles of the thoracic region (PI. XXXIa. fig. 24) have fine tapering tips, with 
a somewhat broader wing than in the typical Serpula narconensis, though in the latter 
case position often exaggerates the distinction ; but on the whole the extremities are some- 
what shorter than in the latter form. The posterior bristles present similar features. 
The anterior hooks (PI. XXXIa. fig. 25) diverge from those of the ordinary Serpula 
narconensis, being shorter and provided with a proportionally longer dorsal line. Six 
teeth (instead of seven or eight) only occur above the great fang. The figure of the hook 
in each form approaches that of an equilateral triangle. "Well-marked striae cross the 
1 Ann. and, Mag. Nat. Hist., 1876, ser. 4, vol. xvii. p. 322. 
2 Proc. Linn. Soc. New South Wales, 1884, vol. ix. (sep. copy) p. 20. 
^ Journ. Linn. Soc. Land., 1864, vol. viii. p. 20, pi. ii. fig. 6. 
