294 DEEP SEA FISHES. 



of the dorsal. The distance from the anal to the origin of the ventrals is 

 nearly equal to the depth of the head, that is a little more than half the 

 length of the head. Pectorals short and broad, not reaching to the bases 

 of the ventrals. 



Desci-iption taken from a specimen sixteen and one half inches in length. 



Entire surface and linings of the body cavities deep black. 



Formulas and size of scales would bring this species close to A. Agassisii 

 G. B., but the latter is less elongate, and has a shorter snout and more 

 curvature on the forehead. A. productus Gill has a smaller eye, larger scales, 

 and less elongation than the present form. A. Blanfordi Ale. is probably a 

 close ally of A. fundulus ; the former is figured without a lateral line. 

 Distinguished from A. tenehi^osns Gilb. by the smaller number of scales above 

 the lateral line, by the small scales of the lateral line, by the longer maxil- 

 lary, by the greater length of the base of the anal as compared with that 

 of the dorsal, and by the greater length of the body in front of the dorsal 

 fin. 



IIALOSAUROIDS. 

 HALOSAURID^E. 



In the report on the deep sea fishes obtained by the "Challenger" Expe- 

 dition, published in 1887, this family was treated as if composed of a single 

 genus, Halosaurus ; in the latest publication on the collections of the 

 " Investigator," 1896, tlie treatment is the same. The same arrangement 

 is followed in the present report, excepting that the genus is divided into 

 two subgenera, the first of which, witli //. Owcnii Johns, as the type, is 

 characterized by scales on the crown and forehead and by little or no to 

 moderate enlargement of the scales of the lateral line, and the second, 

 having for types H. rosiratm Gunt., and II. macrochir Glint., is distinguished 

 by absence of scales on the top of the head and by much enlarged scales 

 on the lateral line. On alcoholic specimens of the two subgenera there is 

 a difference in the luminous organs which probably appears to some extent 

 on the living individuals ; the membranes covering the lanterns are nearly 

 or quite transparent on //. Owcnii and its allies of the first group, while on 



