FISHES. 



141 



usually fang-like. Unlike the Scopelidas, the lateral margins of the npper jaw are 

 formed by the maxillaries, which are provided with teeth. At the throat, in all the 

 known species, is a long fleshy barbel. The opercular apparatus is incomplete, and, as 

 usual in fishes inhabiting great depths, the skeleton is imperfectly ossified. Some of 

 them {Astronesthes) have the adipose fin, but most have not. The phosphorescent 

 spots are numerous, and, as already described, are more specialized than those found 

 in the Scopelidae, bearing much resemblance to true eyes. The Stomiatid83 are all 

 comparatively small, although evidently, in their proper element, ferocious fishes. 

 About a dozen species are now known, from the deep seas of various regions. About 

 six species, representing the principal types, have been obtained by the ' Fish Hawk,' 

 and the ' Albatross,' the dredging steamers of the United States Fish Commission, off our 

 Atlantic coast. Of Malacosteics niger, another deep-sea type, specimens are exceed- 

 ingly rare, although the genus has long been known. Its relations are still obscure. 



Fig. 90* — Malacosteus niger. 



Closely related to the Stomiatidse are the Stbenoptychid^. These fishes have a 

 similar structure of the mouth, but the teeth are small, and there is no barbel at 

 the throat. The body is rather deep, naked, and covered with silvery pigment, 

 instead of black as in the Stomiatids9 generally. The adipose fin is present. The 

 phosphorescent spots are of the less specialized type seen in the Scopelidae. About 

 a dozen species are known, all small fishes, of the deep sea. It is, however, 

 probable that they are surface fishes, descending in the daytime, rather than true 

 member^ of the deep-sea fauna. Four species have been taken in the Gulf Stream, 

 off our coasts. 



The Chauliodontiu^ are allied to the Sternoptychidse, but having the body elon- 

 gate, and covered with small scales. The mouth is in most cases very large, and the 

 teeth are more or less unequal. In the typical genus, Chauliodus, the teeth are inor- 

 dinately developed, some of them being more than one third the length of the head. 



