34 DEEP SEA FISHES. 
Isistius brasiliensis. 
Scymnus brasiliensis Quoy and Gaimard, 1824, Freycinet’s Voyage, Zool., I., 198. 
Squalus (Scymnus) fulgens F. D. Bennett, 1840, Narrative of a Whaling Voyage, IT., 255; 
G. Bennett, 1860, Gatherings, 66. 
Scymnus (Scymnus) brasiliensis Miller and Henle, 1841, Plagiost., 92, with varieties S. torguatus 
and S. unicolor, both of which are credited to Valenciennes ; Dum., 1865, Elasm., 453. 
Dalatias brasiliensis Gray, 1851, Chondropt., 76. 
Leius ferox Kner, 1865, Denkschr. Ak. Wien, XXIV. (for 1864, Nov. 10), Extr., p. 10, Plate 4, 
fig. 2, described and figured. 
Tsistius brasiliensis Gill, 1865, Pr. Phil. Ac., 264 (for 1864, Nov. 22), name only; Giint., 1870, 
Cat., VIII, 429, described; Pet., 1876, Sb. Brl. Akad., 853, locality. 
Plate I. fig. 1, Plate If, III, Plate LXIX. fig. 2. 
Body elongate, subcylindrical, tapering behind the middle, slender in the 
caudal region, body cavity extending through the anterior two thirds of 
the total length. Head small, length to the hindmost gill opening less than 
one fifth of the total, subconical, depressed to a very low arch or nearly flat 
on the crown, wider than high. Snout short, blunt, rounded, hardly as long 
as the orbit, little broader than deep. Nostrils, small, anterior, rather close 
together. Mouth of medium size, inferior, slightly backward of a vertical 
from the hind border of the orbit, transverse, with a deep groove in front of 
the upper lip, and a deep fold behind each angle reaching more than half 
way to the first gill opening. Upper lip distinct, separate from the lower ; 
lower labial folds lateral, short, narrow, rounded, at the angle of the mouth, 
attached to the labial cartilages, not extending toward the symphysis on the 
lower jaws. Upper teeth small, raptorial, oblique, acuminate, movable, in 
thirty-three longitudinal rows, several of the transverse series in function 
at the same time, Plate II., fig. 8; lower teeth large, sectorial, erect, fixed, 
broad, thin, sharp angled on the middle of the cusp, smooth on the cutting 
edges, decreasing in size from the median to the outer tooth, which is 
shortest and broader, interlocking on the edges so as to form a continuous 
saw-like plate of thirty-one teeth, all of which are in function at once, Plate 
II., fig. 9. The number of teeth noted by Giinther (25) and that by Kner 
(26) were taken from young individuals. Eye large, nearly one sixth of the 
length to the hindmost gill aperture; pupil round; orbit longer than high, 
not angled in front, with an angle on the hind border where the upper edge 
overlaps the lower; no nictitating membrane. Spiracles moderately large, 
superior, nearly transverse, Plate II., fig. 1. Gill openings five, narrow, 
