DISCUSSION OF SPEI IKS AND THEIR DISTRIBUTION. 495 



to tlic [>rey swallowed, this easily is suspended as a large sac from the lower part of the 

 body, and Boats in the water. The upper and lower jaws arc armed with a series of teeth, 

 which are very unequal in length, some being very long, others small, all are verj slender, 

 and can be depressed toward the inside of the mouth. This peculiarity of the teeth inaj 

 be observed in the Lophius, in the pike, and numerous other rapacious fish with long slender 

 teeth. The vomer is armed « ifh a transverse series of single teeth, and extends across the 

 whole width of the roof of the mouth; the palatines ami pterygoid teeth are situated at 



some distance behind the v sr, and form two bundles irregular in form. The pharynx 



anil oesophagus are, as might be expected, very wide. The eye is situated high up on the 

 side- of the head: it is very small, covered by, but appearing through, the skin. There are 

 no nasal openings. The opercular pieces are reduced to styliform rudiments; there are 5 

 branchiostegals. Only the three inner branchial arches bear short branchial lamellae, 

 which are disposed in a double series on the two middle ones, and in a single one on the 

 innermost arch. The gill opening itself is a slit of moderate width, below and behind the 

 pectoral tin. The upper surface of the head is concave, and in the middle of its anterior 

 portion there is situated the single filament to which the anterior dorsal fin is reduced; 

 this filament is more than half as high as the head, and dilated into a small lamella at its 

 extremity. The second dorsal fin occupies the back of the tail, and is composed of 14 

 simple rays, none of w Inch are as high as the fin is long. The caudal tin is quite free from 

 the dorsal and anal, and composed of s very soft rays, which are bifid at the end, and 

 form a convex posterior margin. Anal tin very short, composed of 4 rays only, which are 

 opposed to the posterior dorsal rays. The base id' the pectoral tin is fleshy and enveloped 

 in skin, as in other Pediculati. It is composed of 18 simple and feeble rays. Ventral tins 

 none. Vent situated immediately behind the abdominal sac. The whole fish, even the 

 inside of the mouth of the abdominal sac and of the stomach, is of a uniform black. 



Total length (mouth closed), 3.8 inches; length of intermaxillary and of mandible, 1.4 

 inches. 1 



LIOCETUS, Glinther. 



Lioeetua [subgenus], Gunther, Challenger Report, xxn, 1887,57. [Type, Melanocetus Murrayi, Oiinther.] 

 The subgenus I/iocetus of Gunther differs from Melanocetus chiefly in the absence of 

 vomerine teeth. 



LIOCETUS MURRAYI, Gonthek. (Figure407.) 



Melanoa tus bispinoaus, Gunther., Stud; of Fishes, 18X0, 473. (Name only.) 

 Melanocetus {Liocetua) Murrayi, Gunther Challenger Report, \.\n, 1887, pi. xi, fig. a. 



Extremely similar to Melanocetus Johnsonii, but, singularly, there is no trace of vo- 

 merine teeth, whilst there is no distinction between the two species as regards the den- 

 tition of the jaws. The posterior angle of the mandible, projects more and forms a 

 salient point. The mouth is comparatively less wide, and the maxillary considerably shorter, 

 being about two-fifths of the total length, without caudal, whilst it is rather more, than one- 

 half in the Madeiran species. Eye rudimentary. One cephalic spine, which is shorter than 

 the maxillary. The last dorsal ray is connected by a short and delicate membrane with 

 the caudal tin; most of the caudal lays are bind, the longest shorter than the maxillary. 

 Pectoral tin as much developed as in .1/- lanoa tus Johnsonii. 



Entirely black. 



Linea. 



Total Length II 



Length of mandible II 



Length of maxillary VJ 



Length of caudal fin 10J 



Radial formula: D. 1-13; A. 4: 0.9; P. 14.— Gunther. 



A young specimen, 14 lines in length, was taken by II. M. 8. Challenger in the mid- 



1 G( m iii b, Proc. Zool. Soc., 1864. 



