306 Mr. A. Alcock on the Bathyhial 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 j those in the jaws 

 Btanding, uncovered by the lips, outside the mouth ; those in 

 the premaxillse and mandible recurved, quadriserial anteriorly, 

 and laterally triserial in the former, biserial in the latter ; 

 those in the maxillas 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-laminsB very narrow, the individual 

 lamellse extremely delicate. Pseudobranchise 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 cseca 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 premaxillse and mandible. 



