270 DEEP SEA FISHES. 
Dactylostomias, in which the head resembles that of Astronesthes and the 
body that of Stomias. In this new genus the pectoral is more degraded than 
those of Opostomias or of Echiostoma since the fin properly so called has dis- 
appeared and left only the single long filamentary ray. The nearest ally of 
Dactylostomias is probably Grammatostomias, from the northwestern Atlan- 
tic, in which genus however the pectoral fin has been retained without the 
detached or isolated ray. 
CHAULIODID &. 
Chauliodide Bonap., 1845; Chauliodontide Bonap., 1846. 
The barbel possessed by the species of the genus Chauliodus has appar- 
ently been entirely overlooked by all authors who have dealt with the 
members of this family. The organ is small but distinct on the compara- 
tively well known species Chauliodus Sloani, and is rather more distinct on 
other forms (see Plate K, figs. 3 and 2a, on which it is outlined from below as 
seen on C. barbatus and C. Sloani). It is a fleshy, pointed, worm-like append- 
age situated on the chin between the angles on the lower edge of the lower 
jaws. It is translucent and contains a series of isolated black bodies, each of 
which bears a reflecting facet on the lower (hinder) side. A larger luminous 
organ rests below the base, and more or less backward from this there are two 
others. From the muscles used in the control of its movements, its function 
is probably one of considerable importance. In classification the presence of 
the barbel necessitates the removal of the genus farther from Gonostoma and 
other Sternoptychoids, and places it nearer to the Stomiatoids. It empha- 
sizes the necessity of adopting Bonaparte’s family, the Chauliodida. On all 
of the five or six known species an adipose dorsal fin is present. The vari- 
ous published figures representing Chauliodus without this fin are incorrect 
(for instances see Bl. Schn., 1801, pl. 85,—Shaw, 1804, V, pl. 111,— 
Swainson, 1838, I, fig. 65, — Valenciennes, 1850, pl. 97, fig. 3). On the 
other hand those illustrations which represent species of Chauliodus with a 
second dorsal containing rays like those of the anal fin are equally erroneous 
(see Risso, 1826, III., fig. 37, — Bonaparte, 1841, Fauna Ital., — Giinther, 
1880, Introduction, fig. 285). 
These fishes no doubt frequent considerable depths, but whether they 
habitually stay close to the bottom is still an open question. The greatest 
depths were assigned them by the “ Challenger,” northeast of the Bermudas, 
