230 
THE VOYAGE OF H.M.S. CHALLENGER. 
Nereis [Ceratonereis) hrasiliensis, n. sp. (PL XXXVI. figs. 1, 2, 3; PI. XVII a. 
figs. 3, 4). 
Habitat . — Trawled at Station 122b (off Barra Grande, Brazil), September 10, 1873; 
dat. 9° 9' S., long. 34° 53' W.; depth, 32 fathoms ; surface temperature, 77°'5 ; sea-bottom, 
red mud. 
Head nearly as long as broad ; tentacles about two-thirds the length of the head. 
Eyes of moderate size, devoid of lenses. Tentacular cirri short, the longest scarcely 
reaching the third segment. Paragnathi — I. absent ; II. double rows of large points ; 
III. two teeth ; IV. ovoid patches of large points ; V. to VIII. absent, the basal ring of 
the proboscis being devoid of paragnathi. Brownish maxillae have four to five teeth 
below the fang. The first segment is decidedly broader than the next. Feet have rather 
long conical lobes. The superior bristles have comparatively short tips ; the falcate 
forms have somewhat elongated extremities, often with a convex spinose margin. 
A small Nereis, about 34 mm. in length and 3 ’5 mm. in breadth at its widest region. 
There is nothing very characteristic in the external ajDpearance of the form, except 
perhaps the short tentacular and other cirri, and the coloured glandular masses on the 
posterior feet. 
The head (PL XXXVI. fig. 1) is nearly as long as broad. The slightly tapered ten- 
tacles are about two-thirds the length of the head. The tentacular and other cirri are 
short, the longest scarcely reaching the third body-segment. The four large eyes are 
devoid of lenses, and occupy the lateral margin posteriorly. 
The buccal segment is slightly longer {i.e., in antero-posterior diameter) than the 
next. The buccal region of the proboscis has no paragnathi. Two black paragnathi 
(III.), one in front of the other, occur on the ventral median lozenge between the 
maxillse. On the elevation close to the inner side of each maxilla is an ovoid patch 
(IV.) of about a dozen distinct blackish paragnathi. On the dorsal arch of the proboscis, 
after withdrawal, are two elongated rows of eight or nine well-marked blackish points 
(II.). They are so arranged as nearly to form a double row in each group. There are 
none in the middle maxillary region superiorly ; and the basal ring of the organ is 
entirely devoid of them. The brown maxillae have respectively four and five teeth below 
the tip. The region of the alimentary canal immediately succeeding the proboscis has its 
internal surface covered with unusually distinct conical glandular papillae. 
The tenth foot (PL XXXVI. fig. 2) has a dorsal cirrus considerably longer than the 
superior lobe, which nearly forms an isosceles triangle. The second lobe shows a rounded 
accessory one at its base, and is bluntly triangular, with a long inferior and a short 
superior margin. Its tip projects nearly as far outward as that of the superior lobe. The 
inferior setigerous division is less prominent than the foregoing. The ventral is somewhat 
