42 
NATURAL HISTORY. [UPPER FLOOR. 
species have a ridge of cartilaginous spines on the side of the 
tail. The Sword Fish ( Xipkias ) is very like the Tunny, 
but the front part of its upper jaw is produced into a long 
beak, with which it attacks the larger sea animals. It swims 
with excessive rapidity, and its flesh is much praised. The 
common Sword Fish ( Xipkias gladius) has no ventral fins. 
The Flying Sword Fish (Jsfotistiuin) has distinct ventral fins, 
and the dorsal very high and long, which enables it to swim 
with such velocity that it can drive its beak through the 
stout oak planking of a ship. A fine specimen of this fish 
is in a Case over the Fire-place, and by the side of it a 
piece of oak plank pierced by the beak of a larger fish of 
this species. The fish itself is very rare, yet several well 
recorded instances of similar occurrences are known. In 
many genera of the Scomberoid family, the spines, which 
in most fishes support the front dorsal fin, instead of being 
united together, are separate and free. This is the case 
with the Pilot Fish ( Gasterosteus ductor), and the Lichia 
(Scomber glciucus ). 
The next family of spinous fishes, the Tsenioids ( Ccepo - 
lidce,) resemble the Scombers in general appearance, but their 
bodies are very long and compressed on the sides, from whence 
they are called Riband Fish. One of these, the Garter 
Fish ( Lepidopus ), has the mouth long, and well armed with 
teeth, and the ventral fins reduced to small scales. This 
is the Zipotheca tetradens of Colonel Montague, who found 
it on the English coast. The Riband Fish ( Cepdla ) differs 
in having a small oblique mouth and short muzzle, with 
the dorsal and anal fin united into a point at the tail. Over 
the Mantel-piece is also another fish of this family (Lo- 
photes), from the Mediterranean; its short head is sur¬ 
mounted by an elevated bony crest, from the top of which 
springs a long spinous ray, fringed behind by a broad mem¬ 
brane, and having the appearance of a feather. 
The family of Theutides ( Tlieutidce ) combine with the 
small scales of the Scomberoid Fish the form and small 
mouth of the Chaetodon, but are furnished with a single row 
of teeth with cutting edges, and their fins are not scaly. 
They live on fuci and other marine vegetables. Several of 
the genera have sharp, retractile spines on the sides of the 
tail, which when drawn back are received in a groove, and 
from the w T ound they inflict they are often called Lancet 
