148 
NATURAL HISTORY. 
[n. ZOOL. GAL, 
The Hammer-headed Shark ( Zygena ) is peculiar for the head being 
flattened, truncated in front, and extended horizontally on the sides, so 
as to resemble a hammer. The Sea Angels (Squatina) have a de¬ 
pressed body, and the mouth placed at the end, and not beneath the 
muzzle. The Saw Fish ( Pristis) have, with the long body of the Sharks, 
the branchial opening below, and the muzzle produced into a long blade 
armed on the sides with implanted bony spines. This instrument, 
whence they derive their name, is so powerful, that they do not fear to 
attack the largest cetaceous animals. 
The Rays (Raid^e) are known by their flattened bodies, by their 
large fleshy and expanded pectoral fins, united in front to the muzzle, 
and behind to the ventral fin and the spine. The mouth of most of 
them is armed with tubercular teeth placed in close quincunx order on 
the maxillae. Their eggs have a brown coriaceous shell, of a quadran¬ 
gular form, with the angles prolonged into points. The tail of some, as 
the Rhinobates ( Phinobatus ) and Rhine ( Rhino, ), is thick, like those of 
the sharks ; in others, as the true Ray ( Raia ), it is slender, and often 
armed by small spines. In the Sting Ray ( Trygon) it is very long and 
slender, and armed with a long bony spine, serrated on both its edges. 
The teeth and caudal spines of these fishes are often found in a fossil 
state, when the former have been called palates. The Sea Eagles 
( Myliobatis) have a long tail like the Sting Rays, but their pectoral 
fins are very broad, so that they in some measure resemble a bird of 
prey with its wings extended. The teeth of the Sea Eagle are large 
flat plates, arranged in a tessellated form. The Cephalopterse ( Cepha - 
Joptera) very much resemble the Sea Eagles, but their head is trun¬ 
cated in front, and the anterior edge of the pectoral fin expanded like 
two horns. The Electric Ray ( Torpedo) is peculiar for its fiddle-shaped 
body. 
The last family of fishes is that of the lampreys ( Petromyzid^e), 
whose skeleton is the most imperfect of all the vertebrated animals. 
Their body is long, slender, and cylindrical, ending in a circular mouth, 
and destitute of pectoral and ventral fins. The true Lamprey ( Petromy - 
zon) has seven branchial openings, whence their vulgar nlme Seven 
Eyes, and the skin under the tail forms a kind of fin. Their mouth is t 
armed with teeth. The Gastrobranchus ( Gastrobranchus) differs from 
the Lamprey by the tongue only being armed with teeth, like the 
Lobworms. These animals emit such a quantity of mucus through the 
pores of the lateral lines, that it converts the water in which it is placed 
into a jelly. 
Order I. Acan- b. Aspidiphores. 
THOPTERYGfA. c. Platycephalus. 
Fam. 1. Triglidas. 
a. Trigla. 
Prionotus. 
Peristedion. 
? Cephalfcanthus. 
b. Dactylopteres. 
Fam. 3. Scorpcenidce. 
a. Hemilepidotes. 
Blepsias. 
Temnistia. i 
Apist^s. 
Tsenianotus. 
> i '/ 
Fam. 2. Cottidce. 
a. Cottus. 
Hemitripteres. 
Bemb/at 
Oplicntnys. 
Micropus. 
Scorpaena. 
Sebastes. 
b. Pterois. 
Pelors. 
c. Synance^e* 
Agriopus. 
Hoplostethus. 
Fam. 4. Polynemida. 
Polynemus. 
Fam. 5. Cirrhitidce. 
Aplodactylus. 
Cirrhites. 
Chironemus. 
Cheilodactylus. 
Fam. 6. Percidce. 
a. Perea. 
Labrax. 
Lates. 
Centropomus. 
Grammistes. 
Aspro. 
Huro. 
E tel is. 
Niphons. 
Enoplosus. 
Diplop rion, 
Apogon. 
Cheilodipterus. 
Pomatomus. 
Ambassis. 
