44 Isospondyli 
ceous of Mount Lebanon. Many other species are found in the 
European and American Cretaceous rocks, but are known from 
imperfect specimens only. 
Sardinius, an American Cretaceous fossil herring, may stand 
near Spaniodon. Rhacolepis buccalis and Notelops brama are 
found in Brazil, beautifully preserved in concretions of cal- 
careous mud supposed to be of Cretaceous age. 
The extinct family of Pachyrhizodontide is perhaps allied 
to the Elopide. Numerous species of Pachyrhizodus are found 
in the Cretaceous of southern England and of Kansas. 
The Albulide.—The Albulide, or lady-fishes, characterized by 
the blunt and rounded teeth, are found in most warm seas. 
Fic. 31.+The Lady-fish, Albula vulpes (Linneus). Florida. 
Albula vulpes is a brilliantly silvery fish, little valued as food. 
The metamorphosis (see Fig. 112, Vol. I) which the larva under- 
goes is very remarkable. It is probably, however, more or less 
typical of the changes which take place with soft-rayed fishes 
generally, though more strongly marked in Albula and in certain 
eels than in most related forms. Fossils allied to Albula, Albula 
owent, Chanoides macropomus, are found in the Eocene of Europe; 
Syntegmodus altus in the Cretaceous of Kansas. In Chanoides, 
the most primitive genus, the teeth are much fewer than in 
Albula. Plethodus and Thryptodus, with peculiar dental plates 
on the roof and floor of the mouth, probably constitute a dis- 
tinct family, Thryptodontide. The species are found in Euro- 
pean and American rocks, but are known from imperfect speci- 
mens only. 
The Chanide#.—The Chanide, or milkfishes, constitute another 
small archaic type, found in the tropical Pacific. They are 
