170 



bones, which are extremely thin, are invested by the same tough black skin that 

 covers the head ; the gill-lamina? are coarse and the gill-rakers on all the arches 

 long and lamellar ; pseudobranchias small. 



Head naked, body covered with large cycloid scales, which are deciduous 

 everywhere but on the lateral line ; small scales also invest the bases of all the 

 fins. A scale from the flank measures about 7*5 millim. in the horizontal and 

 about 5'5 millim. in the vertical diameter. 



The dorsal and anal fins arise just in advance of the posterior third of the 

 body (measured without the caudal), and the base of the former, which begins a 

 little in advance of the latter, is two-thirds that of the latter in extent. Caudal 

 deeply forked, with very numerous rudimentary rays at its base. Pectorals 

 broad, in length a little more than the postorbital portion of the head. The 

 ventrals arise just abaft of midway between the pectorals and anal ; they are 

 broad and reach more than halfway to the anal. 



Stomach small, siphonal. The intestine, which, when unravelled, is about 2- 



times the entire length of the fish, consists of two portions, which both in 

 structure and arrangement are quite different from one another : the anterior 

 five-sixths is thin-walled and of small calibre, and is intricately coiled in a globu- 

 lar mass situated in the anterior fourth of the abdomen, the coils being held by 

 a long mesentery ; the posterior sixth is wide, but with walls so thick as to 

 almost block the lumen (in the contracted state), the mucosa in this condition 

 being thrown into numerous longitudinal folds ; it passes straight down the 

 middle of the abdominal cavity unsupported by mesentery. There are nine 

 large long pyloric casca in a pectinate arrangement. 



In a female with much-enlarged ovaries containing ova nearly -i millim. in 

 diameter the ovaries extend back to the wide genital pore, through which they 

 open to the exterior. 



Colours in life: — Head, including sclerotic and iris, black; body uniform 

 dull slate-blue ; pharyngo-brancbial mucous membrane and parietal peritoneum 

 black. 



Adult females are just under a foot in length : adult males are a good deal 

 smaller. 



Bay of Bengal, off Ganjam coast, 240 to 276 fathoms; Arabian Sea, off 

 Malabar coast, 360 fathoms. 



Regd. Nos. 13079, 13080, 13081, 13083, ™. 



The microscopic structure of the hind-gut of Alepocephalus bicolor. 



In transverse section the appearance somewhat resembles that of the human 

 vas deferens. Externally there is a thin fibrous coat containing blood-vessels, 

 and internal to this and intimately adherent to it is a thin layer of longitudinally- 



