266 DEEP SEA FISHES. 
The scales behind the adipose dorsal, appear to cover luminous bodies ; 
the adipose fin, and mucous matter in the cavity in the middle of the inter- 
orbital space and around the nasal sacs probably also are luminous. The 
iris has the golden color of the lanterns and if not luminous itself must act 
as a reflector. 
Brilliant iridescent bluish to silvery and golden on the scales and head, 
blackish when the scales are lost, darker on the back, lighter on the fins, 
whitish on the snout; lanterns and iris golden. 
Station. Latitude. Longitude. Temperature. 
3382 6° 21’ N. 80° 41’ W. Surface 75° FB. 
Myctophum nitidulum psp. n. 
Plate LVI. fig. 3. 
Dal ALTO ViSe Pos. iA: 
This species is somewhat closely allied to IM. Caninianum C.V. The 
differences in shape, position of fins, and in the numbers of rays and of 
scales are small, and the arrangements of the lanterns present great simi- 
larities in the two species ; but there are dissimilarities in the groupings of 
the lanterns that, taken in connection with the slight variations in the 
numbers of the lanterns, of the rays, and of the scales and in the shape of 
the head, make it necessary to describe and figure this form as distinct. 
The body is quite as slender as that of M. Caninianum, but the head is rather 
more full and blunt on the snout, the eye is smaller, and the number 
of lanterns in the post anal group, Liitken’s anales posteriores, is five instead 
of eight. Another form to which the present bears considerable resem- 
blance is IZ. affinis Liitk., which has the same numbers of lanterns in the 
groups, but has a less distinct separation of one group from another, and 
the eye is larger, the snout shorter and less pointed and the number of 
scales in the lateral line is smaller in that species. 
Body and head compressed, caudal region of moderate slenderness. 
Length of head one fourth and depth of head two elevenths of the total 
length. Mouth wide; maxillary two thirds as long as the head, hardly 
expanded at the end. Eye large, little less than one third of the length ot 
the head. Anal origin slightly forward of the middle of the entire length, 
third or fourth ray below the base of the hindmost ray of the dorsal. First 
dorsal ray midway from the snout to the middle of the distance from the 
