306 Mr. A. Alcock on the Bathybial Fishes 
posed of three longitudinal plates, of which the innermost 
(uppermost) is movable ; the mandible is very strong and 
broad, and its under surface is excavated for a wide mucous 
channel which opens by six large circular pores on each side. 
Teeth small, even, uniform, acute ; those in the jaws 
standing, uncovered by the lips, outside the mouth ; those in 
the premaxillae and mandible recurved, quadriserial anteriorly, 
and laterally triserial in the former, biserial in the latter ; 
those in the maxillae uniserial, procurrent or procurved ; those 
in the palatines uniserial, incurved ; those in the vomer 
recurved, in a group of two or three on each side. Tongue 
large, toothless. 
Gill-openings very wide; gill-membranes entirely separate; 
gill-covers large, complete ; gill-rakers decreasing in size 
from the first arch to the fourth, those on the first arch being 
close-set, finely pointed, and as long as the eye ; fourth gill- 
cleft rather wide ; gill-laminae very narrow, the individual 
lamellae extremely delicate. Pseudobranchiae large. 
Head naked ; body covered with deciduous scales of mode- 
rate size. The lateral line runs straight along the middle of 
the body. 
The dorsal fin begins almost in the vertical through the 
origin of the ventrals, which are situated a snout-length 
behind the vertical through the middle of the body measured 
without the caudal. The anal fin begins two rows of scales 
behind the vertical through the hinder limit of the dorsal. 
No adipose dorsal. Caudal symmetrically forked. Pec- 
torals and ventrals well developed, broad, fragile. 
Stomach very large, with thick walls thrown into deep 
longitudinal folds ; the organ must be widely distensible in 
correlation with the wide mouth. Intestine coiled in a spiral ; 
ten very large pyloric caeca in a bunch. No air-bladder. 
Ovaries with an oviduct. 
Colours in the fresh state : — Head, iris, body, fins, oro- 
pharyngo-branchial membrane, and entire peritoneum deep 
black. 
Two female specimens, measuring respectively 13| and 9^ 
inches. 
Station 105, 740 fathoms. 
Both specimens when brought on board were in a cata- 
leptoid state, the whole muscular system being quite rigid, 
and cutaneous excitation eliciting no responsive movement. 
I have separated this fish from Bathytroctes chiefly on 
account of the pluriserial teeth in the premaxillae and mandible. 
