XXI 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." 
The Pachyrhizodontidae, with the Cretaceous genus Pachy- 
rhizodus, are placed by some authors with the Salmonidae, 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,’ the rayed fin being 
situated far back on the body, in the caudal region, and opposed 
1 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), Smitt, Krit. Forteckn. 
Riksmus, Salmonider (1886), Fatio, Faune des Vertébrés 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. 
