95 



Gill-openings wide: operculum with a feeble flat spine. Eight branchi- 

 ostegals. No pseudobranchia?. 



Dorsal and anal fins confluent with the caudal. 



No ventral fins. 



A small air-bladder present. Pyloric appendages few and small. 



The curious Halosanrus-like lateral line and the absence of ventral fins and 

 pseudobranchiae distinguish this genus from Glyptophidium, which it otherwise 

 closely resembles. 



Key to the species of the genus Lamprogrammus. 



I. The angle of the preoperculum is simply notched ... L. niger. 



II. Three weak flat teeth at the angle of the preoperculum ... ... L.fragilis. 



74. Lamprogrammus niger, Alcock. 



Lamprogrammus niger, Alcock, Ann. Mag. Nat. Hist., Jnly 1891, p. 33, fig. 2 : Illustrations of the Zoology 

 of the Investigator, Fishes, pl. I. fig. 2. 



D. circ. 110. A. circ. 90. P. 17. V. 0. 



Length of the head about one-fifth of the total, greatest body height (at 

 the shoulder) equal to the length of the head without the snout. 



Length of the snout about twice that of the eye, less than the width of the 

 convex interorbital space. 



The major diameter of the eye is an eighth or a ninth the length of the 

 head. 



The upper jaw, the length of which is half that of the head, overlaps the 

 lower. Villiform teeth in a broad band in the upper jaw, in a narrow band on 

 the lower jaw and on each palatine, and in a narrow broken A-shaped band on 

 the vomer. 



Angle of the preoperculum notched, the angles of the notch rounded off. 

 About ten long gill-rakers on the outer side of the first branchial arch. 



Body and head covered with deciduous, almost membranaceous, scales of 

 moderate size. 



The scales of the very conspicuous lateral line are adherent and greatly 

 enlarged; they lie beneath a continuous sheath of black skin, which is loopholed 

 over a long narrow groove with raised margins situated along the vertical 

 diameter of each scale. These grooves are filled with an opaque white substance, 

 which probably has a luminous function. The lateral line, in fact, is exactly 

 similar to that of several species of Halosaurus. 



