MALACOPTERYGII 569 



quivering mass of eggs and sand. Plecoglossus, from Japan and 

 Formosa, is highly remarkable for its lamellar, comb-like, lateral 

 teeth. The Siel-Smelts (Argentina) are deep-sea Salmonids of 

 which examples have occasionally been taken off the coasts of 

 Scotland and Ireland ; large numbers have been brought from 

 Norway to English markets. Bathylagus is still better adapted 

 for life at great depths (down to 1700 fathoms), the eyes being 

 of enormous size. As Dr. Giinther has observed, " these fishes 

 must be entirely dependent for vision on the phosphorescent 

 light which is produced by other abyssal creatures. Not being 

 fish of prey themselves, or only to a slight degree, they would be 

 attracted by the light issuing from the Pediculates and Stomiatids 

 of the deep, and thus form an easy prey to these fishes." 



Secondary sexual characters are very strongly developed in 

 many Salmonids. In adult males of Salmon, Trout, and Quinnat 

 the snout becomes greatly distorted, both jaws being hooked and 

 the base of the teeth more or less enlarged; in the latter species 

 a fleshy hump is developed before the dorsal fin, and the scales of 

 the back become embedded in the flesh. Pearl-like excrescences 

 appear on the scales of many of the White-Fish during the breed- 

 ing season, being more prominent in males than in females, and 

 Mallotus villosus is so called from the villous bands formed by 

 the scales of mature males, the scales above the lateral line and 

 along each side of the belly becoming elongate-lanceolate, densely 

 imbricated and produced into free, projecting points. 1 



The Pachyrhizodontidae, with the Cretaceous genus Pacliy- 

 rhizodus, are placed by some authors with the Salmouidae, but the 

 remains at present known are too fragmentary to afford a correct 

 idea of their exact systematic position. There seems to be less 

 justification for placing them among the Elopidae. 



Fam. 18. Alepocephalidae. Deep-sea Fishes similar in 

 general structure to the Clupeidae and Salmonidae, but destitute 

 of a postclavicle and of an adipose dorsal fin, 2 the rayed fin being 

 situated far back on the body, in the caudal region, and opposed 



. * For important contributions to our knowledge of European and American 

 Salmonids since the publication of Giinther's account in the British Museum 

 Catalogue, cf. F. Day, British and Irish Salmonidae (1887), Sinitt, Krit. Forieckn. 

 Riksmus. Salmonider (1886), Fatio, Faune dcs Verttbrte de la Suisse, v. (1890), and 

 Jordan and Evermann, Fish. N. America, i. (1896). 



2 In Anomalopterus, however, a sort of adipose fin exists, as a fold or cushion on 

 the back, but in front of the rayed dorsal. 



