Jordan and Evermann. — Fishes of NortJi America. 593 



the swallowing of fishes much larger than itself. Teeth pointed, unequal, 

 iu single series on both jaws and tongne ; none on the palate. Eye very 

 large, at very tip of the blunt snout, with two luminous organs below it, 

 the anterior larger and pear-shaped, with the narrow end forward ; sides 

 with luminous spots. Hyoid barbel wanting; a cylindrical muscular 

 band in its place connecting the symphysis of the very thin lower jaw 

 with the front of the hyoid bone. This is probably contractile, "serving 

 to give the extremity of the mandible power of resistance when the fish 

 has seized its prey, as without such a contrivance so long and slender a 

 bone would yield to the force of the struggling victim." * This structure 

 is unique among fishes. No gill rakers. Two species known, in the deep 

 seas. (^a/ia/c6f , soft ; oortov, bone.) 



888. MALACOSTEUS XIGER, Ayree. 



HeadSf; depth, 5i. D.19;A. 20; P. 5; Y. 6. Lower jaw with unequal 

 canines, four of them fang-like and longer than the others. Pectoral 

 rays filamentous. Ventrals filamentous, inserted midway between base 

 of caudal and posterior luminous organ. Black, except the luminous 

 spots. (Giinther.) Open sea, in very deep water ; rare. Known from 

 the Gulf Stream and southward to Barbadoes. (niger, black.) 



Slalacostens nigrr, Ayres, Journ. Bost. Soc. Nat. Hist., 1849, 53, Gulf Stream, 42° N. 60° W.; 

 GuNTHER, Cat., V, 428, 1864; Jordan & Gilbert, Synopsis, 287, 1883; Ginther, Deep-Sea 

 Fishes Oliallengcr, xxii, 214, 1887; Goode & Bean, Oceanic Ichthyology, 114, 1895. 



Family LXXXI. ALEPISAUEID^. 

 (The Lancet Fishes.) 

 Body elongate, rather compressed, scaleless. Head compressed, with 

 the snout much produced, and with the cleft of the mouth very wide. 

 Premaxillaries very long and very slender, forming the entire margin of 

 the upper jaw, not protractile; maxillary thin, ueedle-like, as long as 

 the premaxillary , immovable, provided with a small supplementary bone. 

 Teeth very unequal, immovable, and subject to many variations in the 

 same species ; a series of small teeth the entire length of the premaxillary, 

 those in front sometimes larger and curved ; palatine teeth compressed, 

 triangular, pointed, two or three of the anterior ones exceedingly long 

 and strong, fang-like, the jiosterior ones moderate ; teeth of the lower 

 jaw similar to those on the palatines, one pair in front and two or three 

 pairs in the middle being much enlarged; no teeth on the tongue. Eye 

 large. Gill openings very wide ; the gill membranes not united, free 

 from the isthmus ; gill rakers stiff", shortish, spine-like. Branchiostegals 

 mostly 7. Pseudobranchi;c large. Opercular bones thin, membranaceous. 

 Dorsal fin very long and high, occupying nearly the whole of the back, 

 of more than 40 rays, which are slender and simple, all of themdepressible 

 into a deep groove, the fin invisible when dejiressed ; ventral fins abdom- 

 inal, nearly median, of 9 to 13 rays, the first ray simple, spine-like; 

 adipose fin present, moderate ; anal fin moderate ; caudal fin forked. Air 



*Seo Giinther, Dcep-Sea Fishes, Challenger, xxii, 212, 1887, for a full account of tho structure 

 of this remarkable type of fishes. 



F. N. A. 39 



