NATURAL HISTORY. 
139 
ROOM IV.] 
high and the body compressed, thin ; their bodies are covered with large 
scales. The Chromis have most of the characters of the Labri , but 
the teeth of the jaws and palate are small and hooked ; the rays of their 
vertical fins are produced and thread-like. The Plesiops have a 
compressed head, their eyes close together, and the ventral very long. 
The Malacanthus are like the Labri, but the front rays of the dorsal 
are thin and flexible, and the palatine teeth are small and hooked. 
The Parrot fish ( Scarus ) have large parrot-like jaws, covered with scale¬ 
like teeth. The Calliodon have the teeth on the side of the upper jaw 
separate and pointed. The Odax , with the teeth of the Scari , have 
much the appearance of the Labri; their lateral line is continued. 
Lastly, the Gerres are peculiar for having protractile jaws ; their body 
is high, especially in front of the dorsal, the hinder part of which is en¬ 
closed in a scaly sheath; their teeth are velvet-like. 
The Wandering Fishes ( Anabasidce ) have all the characters of the 
Perches, but the upper part of their pharynx is divided in more or less 
numerous, irregular small leaves, which intercept the passage of the 
water from the gills, and keep them moist, while these fish are left dry, 
or forsake for a time the ditches or ponds in which they usually live ; they 
have only a single dorsal fin. The Anabas has a long dorsal fin and 
radiating ventral ones. The Polyacanthus and the Helostomes have a 
long dorsal fin and filiform elongate ventral ones; the former has 
velvet-like teeth in the jaw, and the latter have none. They are all 
from India. The Spirobranchus are like the Anabas, but their pre¬ 
operculum is toothless, and the operculum ends in two points; from 
South Africa. The Macropodes have a short dorsal fin and longer anal 
fin. The Gourami ( Osphromenus ) have the short dorsal of the former, 
but the first soft ray of their ventral is very much prolonged. They 
have only six gill-rays. The Trichopus differs from the latter in the 
dorsal being shorter, the forehead more convex, and they have only 
four gill-rays; all these fish but the Spirobranchus, which come from 
South Africa, are confined to the ponds of Tropical Asia. 
The Sea Mullets, ( MugtllidjE,) from the peculiarity of their form, have 
been separated into a distinct family, characterized by having two dorsal 
fins, large scales, and a very broad flat head, and covered with polygonal 
plates; they have two separate dorsal fins, the first being provided with 
only four rays; their ventrals are placed rather in front of the base of the 
pectorals; they are furnished with a gizzard, like birds, and live at the 
mouth of rivers, making high leaps. 
The family of Ophicephalim agrees with the former in many cha¬ 
racters, especially in having the same conformation of the pharynx, but 
they have no spines but only simple rays in their fins ; their body is 
elongate, the muzzle short, head scaly; their dorsal and anal fin is long. 
They are very difficult to kill, and are kept by the fishermen in India 
and China to divert the people, shewing them walking on the 
earth. They are perhaps more allied to Amia. 
The family of Atherines (Atherinid^:) are peculiar for having a 
broad silver band on each side of their elongated body. They have 
two dorsals very far apart, the ventral behind the pectorals. A very 
protractile mouth with small teeth, as Atherina. 
The family of Tetragonurid^e have an elongate body covered with 
