114 DEEP-SEA FISHES OF THE ATLANTIC BASIN. 



KEY TO THE SPECIES. 



A. Dorsal and anal moderate (D. 19 ; A. 20). Loral spot longer than eye Malacosteus nicer 



B. Dorsal and anal short (D. 15 ; A. 15). Loral spot shorter than eye M. cuoRISTODActylus 



MALACOSTEUS NKiEK, Aykes. (Figure 138.) 



Malacosteus niger, Ayres, .Tourn. Bost. Soc. Nat. Hist., 1849, 53. — Guntheu, Cat. Fish. Brit. Mas., 1864, 

 V, 428. — GooDK and Bean, Bull. Essex Institute, 1879. 



A Malacosteus witli a somewhat sleuder body, its lieight about one-ciglit of its le.ngtli, 

 without caudal ; with large branchial opening, and with comparatively long dorsal and anal 

 fins, nearly oppo.site (the dorsal slightly in advance), falcate, strong. Luminous body almost 

 crescentic, its length greater than diameter of eye. Fangs shorter than diameter of eye. 

 Ventrals shorter than base of dorsal. Black, with numerous light dots over entire body. 



Eadial formula: I). 19; A. 20 (!); P. 3 (?); V. 5. 



For a long time only a single specimen of this species was known, the type of Ayres's 

 description, 8i inches in length, which was picked up at sea in 40° N. lat., 50° W. Ion. 

 The Bkike obtained a single specimen at Station CXLV, off Barbados, at a depth of 347 

 fathoms. The Albatross obtained several specimens: No. 35520, U. S. N. M., from station 

 2211, in 39° 35' JSf. lat., 71° 18' W. Ion., at a depth of 1,004 fathoms; No. 32100, U. S. N. M., 

 (No. 797, Gloucester donation); No. 39220, U. S. N. M., OJ inches in length, in 37° 40' 30" N. 

 lat., 73° 50' 30" W. Ion.; a specimen from station 2,584, in 39° 05' 30" N. lat., 72° 23' 20" W. 

 Ion., at a depth of 541 fathoms. 



Giinther has described a species very closely related under the name of Malacosteus 

 indicus (Challenger Eeport, xxii, 214, pi. uv, fig. B.), from near the Philippines, 500 fath- 

 oms, and in the Andaman Sea {Alcock) 650 fathoms. 



MALACOSTEUS CHOEISTODACTYLUS, Vaillant. (Figure 139.) 

 Malacosteus choristodactijlus, Vaillant, Exp. Sci. Travailleur ct Talisman, xxii, 1888, 108, pi. viii, fig. 4. 



A Malacosteus with a comparatively stout body, its height nearly one-fourth of its 

 length, its thickness six oiie-hundredths of same, with immense branchial opening by the 

 extent of which the length of the head is seemingly reduced to one-eighth of the length of 

 the body, and with comparatively short dorsal and anal fins inserted nearly opposite each 

 other, apparently rounded and not falcate; caudal fin very small; luminous body under eye 

 sub(piadrangular, its greatest length less than the diameter of the eye; ventrals longer 

 than base of anal, much longer than base of dorsal; the longest ray apparently equal to the 

 distance from insertion of anal to the end of middle caudal rays; length of strongest fangs 

 greater than diameter of eye. Black, apparently without small luminous dots upon the 

 body. 



liadial formula: D. 19; A. 20; C. 12+ ; P. 5; B, 6. 



This species was described by Vaillant from three specimens, two from the coast of 

 Morocco in 1,400 to 1,035 meters and one from the Azores in 2,220 meters. The species is 

 very distinct from M. niger and easily recognized. 



PHOTOSTOMIAS, Collett. 



Photoalomias, Collett, Bull. Societd Zoologiquo do France, 1889, 291. 



A genus allied to Malacosteus, characterized by the absence of pectoral and adipose 

 dorsal tins, and the absence also of teeth upon the iialatiues. The body is compressed, skin 

 naked; ventrals in advance of the middle of the body; vent behind the middle of the body; 

 opercula ludimeiitary. A series of long, crooked teeth in the intermaxillary; teeth upon 

 the lingual and pliaryngeal bones, but absent upon the vomer. Two post-orbital photo- 

 phores. Two rows of photophores along the sides of the belly, and a great number of small 

 luminous points scattered over the entire surfiice of the body. Type, P. Guerni, Collett. 



