396 Mr. A. Alcock on the Bathyhial Fishes 



Diameter of the eye 3^ in the head-length, mucli exceeding the 

 width of the flattened interorbital space. Nostrils large, con- 

 tiguous. Mouth inferior ; the maxilla reaches the vertical 

 from the middle of the orbit. Villiform teeth in the jaws, 

 the outer row in the upper jaw enlarged. Barbel about as 

 long as the eye. Opercular region square, very deep and 

 broad. Gill-openings wide, the membranes united only in 

 front. Gill-laminffi very broad. Scales rather deciduous and 

 uniformly minute, each with about seven short, longitudinal, 

 parallel series of spinelets, the last in each series projecting 

 well beyond the edge of the scale. Eight rows of scales 

 between the first dorsal fin and the lateral line. Second 

 dorsal separated from the first hy an interval equal to the 

 length of the latter's base. Second dorsal spine with large 

 semirecumbent distant barbs. First ventral ray produced 

 into a filament longer than the fin. 



Colours in life : — " Body dull grey ; abdomen slate- 

 coloured ; sides of head and lower jaw silvery ; operculum 

 violet-black ; dorsal fin black, with white root and tip " {Dr. 

 G. M. Giles). 



Two specimens, 5;^ and 6^ inches long respectively, both 

 much damaged. 



Ilah. Bay of Bengal, lat. 20° 17' 30" N., long. 88° 51' E., 

 in 193 fathoms, and lat. 19° 35' N., long. 92° 24' E., in 272 

 fathoms. 



Subgenus Mystaconurus, Gthr. 



Macrurus heterolepis, sp. nov. 



B. 6. D. 11. A. circ. 100. P. 14. V. 10. 



Head much exceeding the trunk in all three dimensions, 

 its mucous-cavities and its bony ridges, except the infra- 

 orbital, well developed. The short trunk falls abruptly to the 

 long filiform tail. Snout truncated, much shorter than the 

 eye, hardly overlapping the upper jaw. Diameter of the eye 

 3| in the head-length and less than the width of the inter- 

 orbital space. Mouth wide, hardly inferior, its cleft reaching 

 the vertical from the middle of the orbit. Jaws slender. A 

 ciliiform barbel about half as long as the eye. Teeth in both 

 jaws in a narrow villiform band. Gill-cleft wide ; the mem- 

 branes united only quite anteriorly. Gill-lamina3 very narrow. 

 Integument thin. Head scaleless. Body covered with very 

 thin and deciduous scales of two forms, those immediately 

 behind the head being large and perfectly smooth, those on 



