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THE VOYAGE OF H.M.S. CHALLENGEE. 
wlien the tip is viewed directly in front or behind. Both anterior and posterior hooks 
are very prominent, generally reaching, in the preparation, the ends of the shafts of the 
dorsal bristles. The ventral bristles are similar to the dorsal, only more slender. 
The greyish pellets (which abounded in the intestine) consisted of finely granular 
mud loaded with multitudes of Diatoms, most being linear. Crustacean hairs, fragments of 
cuticle, and a very few minute Foraminifera. 
This species occupies tubes of greyish mud, lined by the usual tough secretion, and 
strengthened by the long linear leaves of pines, pieces of leaf-stalks and leaves, straws, 
stones, fragments of Echiuoderms, and other structures. The linear leaves of the pines are 
arranged longitudinally, as in the case of the needle-like spicules of the Hexactinellid sjDonge. 
Moreover, as usual, one surface of the tube is better protected than the other, so that the 
latter is probably the lower surface, though this is uncertain. The longest tube measures 
about 80 mm., and has a diameter of 6 mm. at its wide part. A portion of a linear leaf, 
however, projects beyond the aperture. The tube is slightly tapered from before back- 
ward, and somewhat curved. Although in some cases there are two linear leaves of the 
pines, only one is attached to the tube, showing that a rude exterior was important, or 
that full advantage was not taken of the structure. 
In transverse section of a female both dorsal and ventral muscles are somewhat 
flattened, partly from the distention of the perivisceral chamber by large and small ova. 
The disproportion between the dorsal and ventral arches of the circular muscular coat is 
not so marked as in several of the previous forms. The strong oblique muscles pass to 
the circular coat inferiorly, but do not decussate, the rounded nerve-cord occupying the 
space between them, and presenting a small median neural canal. The usual muscular 
arch of fibres from the alimentary canal occurs superiorly. A ventral groove, probably 
due to the contraction of the strong oblique muscles, exists in the middle line. 
Marenzeller ^ describes a form [Onuphis liolohranchiata) from the western shores of 
the Island of Ino Sima, Japan, in which a single large branchial process exists, but the 
anterior feet and the bristles are so characteristically different that no confusion is 
possible, though the dental apparatus is somewhat allied. 
Nothria ivillemoesii,^ n. sp. (PI. XLI. figs. 4-10 ; PI. XXVIa. figs. 1-4 ; PI. XXXVa. 
fig. 1). 
Habitat . — Dredged off Amboina, in 100 fathoms. 
A fragment of the anterior region of the body, measuring about 38 mm. in length 
and 3 ’5 mm. in diameter, is alone available for examination. 
1 Denhsclir. d. math.-nat. h. Ahad. d. wiss. Wien, Bd. xli. p. 24 (sep. Abd.). 
2 Named in hononr of Dr Rudolf v. Willemoes-Suhm, whose promising zoological career was cut short by his 
untimely death during the voyage. 
