GILBERT : CERTAIN SCOPELIDS IN THE MUSEUM COLLECTION. 257 



Distribution of photophores. — A minute round antorbital under the anterior 

 margin of the orbital expansion of the frontal. A somewhat larger suborbital 

 below the anterior portion of the orbit, round and surrounded by black pig- 

 ment, rather smaller than the photophores on tlie body. 



Suprapectoral near lateral line, but not in contact with it ; the usual white 

 glandular body is attached to it below. Upper infrapectoral in front of lower 

 pectoral rays; the lower infrapectoral rather less than halfway from the 

 upper to the first thoracic. 



Thoracics, 5, the fourth elevated, but little behind the third, on a level with 

 upper half of pectoral base; fifth thoracic in front of outer half of ventral 

 base, the first, second, and third near the median line, forming two lines 

 gently diverging backwards. The first thoracic interspace is nearly twice the 

 second, which is a little longer than the fourth. 



Supraventral a little nearer base of ventral fin than lateral line, vertically 

 above middle of ventral base. 



Ventral photophores, 5, the first three pairs forming two strongly diverging 

 lines, the fourth and fifth pairs near the median line, the interspaces all 

 about equal. 



Supra-anals angulated, the upper in contact with the lateral line, a little in 

 advance of anal fin ; the middle spot below and slightly behind the upper, its 

 distance from the upper nearly twice its distance from the lower, the lower 

 halfway between the middle supra-anal and the fifth ventral. 



Antero-anals, 7, the first pair nearest the anal base, the first six pairs 

 forming two very gently diverging straight lines, the seventh a very little 

 elevated above the line of the others, all of them equally spaced. 



Posterolateral in contact with lateral line, over the middle of the space be- 

 tween the two anal groups, above or nearly above the last anal ray. 



Postero-anals, 5, about equally separated from antero-anals and from 

 precaudals. 



Precaudals, 4, the first three close together and equally spaced forming a 

 gentle curve at base of rudimentary caudal rays, the fourth more widely 

 separated, near lateral line, but not in contact with it. 



In the figure of Lampanyctus lacerta giveu by Goode and Bean 

 (loc. cit.) the relative position of the ventral photophores is incorrectly 

 shown ; the last antero-anal should be a little elevated instead of in line 

 with the others, and the fourth precaudal should be more widely sei)a- 

 rated from the third. In addition to the minute antorbital spot, 

 present in the type of D. nodurnus and in all specimens of the species 

 which have come under my observation, there develops in connection 

 with it in some specimens a larger luminous body, which does not, how- 

 ever, extend far out on the snout. The black septum across the photo- 

 phores is less developed in this species than in any other of the genus, 

 being very slender, and usually incomplete in the middle. 

 VOL. xLvi. — No. 14 17 



