SMOOTH-HEADS AND SOUTHERN SALMON. 
49i 
Anchovies. 
Elops. 
The common anchovy of the Mediterranean ( Engraulis encras- 
sichoius ) is the typical representative of a second widely-spread 
genus, with over forty species, differing from the last by the more or less nearly 
conical muzzle projecting beyond the lower jaw, and also by the eyes being covered 
with skin; while the cleft of the mouth is deep, and the tail-fin forked. In most 
cases each side of the body is ornamented with a broad longitudinal silvery stripe. 
The common anchovy is met with off the south-western coasts of England, but 
wanders still further to the north, and serves to supply the markets of the world. 
Some species have the rays of the pectoral fins produced, and thus lead on to the 
allied Oriental genus Coilia, in which the foremost rays of these fins are fila¬ 
mentous, and the exceedingly long anal fin extends backwards to join the caudal. 
A very distinct group, which, as already mentioned, is regarded 
by some as a distinct family, is typically represented by the two 
species of the tropical and subtropical genus Elops. In addition to the characters 
of the skull noticed in p. 487, these fish have the lower jaw longer, a thin plate of 
bone extending backwards from the point of union of the two branches of the 
lower jaw, and the whole under surface of the body smooth and rounded. The 
common species grows to a yard in length. An allied type ( Rhacholepis) occurs 
in the Cretaceous rocks of Brazil. 
The earliest allies of the herring tribe seem to be the extinct 
slender-scales ( Leptolepididce ), of which there are a considerable 
number of species, ranging throughout the Jurassic period. In the typical 
Leptolepis the dorsal fin is placed immediately over the pelvic pair, but in the 
nearly allied Thrissops it is over the anal. Although there are a number of other 
extinct generic types, more or less closely related to the herrings, it is impossible 
to enter into their consideration here, and we accordingly pass on to 
Slender-Scales. 
B IlllSSS 
BLACK SMOOTH-HEAD liat. size). 
The Smooth-Heads and Southern Salmon. 
Families AlMPOCEPHALIDM and HAPLOCniTONlDM. 
The first of these two families is typically represented by the 
genus Alepocephalus, of which a species (A. niger) is shown in the 
annexed illustration. While agreeing with the typical salmonoids in the structure 
Smooth-Heads. 
