ICHTHYOLOGY. 



fion lit' 

 Fishes. 



DIVISION IV. 



' 



Sun fish. 



Cartilaginous fishes, furnished with a gill-lid and gill- 

 flap. 



ORDER XIII. APODAL. 



GfiNUS XIV. OSTRACION. 



Body covered with an osseous coat of mail ; cutting 

 teeth in each jaw. 



This genus contains -fifteen species. They are easily 

 iccognised by the body being covered with an osseous 

 plate, somewhat resembling a tortoise. They are all 

 natives of the seas of warm countries. They feed upon 

 the crustaceous animals, and some of the testaceous 

 mollusca. The flesh is excellent, but small in quantity. 

 La Cepede recommends the 0. triqueter as a fish which 

 he thinks might easily be naturalized in our seas. The 

 O ciibictis, a native of the Indian seas and the Isle of 

 France, is often kept in pools, where it soon becomes so 

 familiar as to come to the surface and eat from the 

 hand. Its flesh is esteemed a great delicacy. 



GENUS XV. TETRODON. Sun-Fish. 



Jaws bony, extending, divided at the tip into two 

 teeth ; gill opening linear ; body round. 



The fishes of this genus, have obtained their present 

 name from the double teeth with wliich their jaws are 

 furnished. La Cepede describes nineteen species, some 

 of which are natives with us. They have the singular 

 power of inflating their abdominal cavity at pleasure. 

 The inflation is produced by air sent from the gills, into 

 a sac formed of a duplicature of the peritoneum, and 

 from thence into the abdomen. The inflation aids the 

 animal in rising in the water, and as the abdomen is in 

 some species covered with spines, it brings these organs 

 of defence into a more favourable position for resist- 



ance. 



GENUS XVI. OVOIDES. 



Jaws bony, extended, divided at the tip into two 

 teeth, destitute of dorsal, anal or caudal fins. 



The single species, for the reception of which Lace- 

 pede formed this genus, was found described among the 

 manuscripts of Commerson. It is an inhabitant of the 

 Indian seas. 



GENUS XVII. DIODON. Globe-Fid. 



Glrfbe-fish. Jaws bony, extended, undivided. 



The globe fish are but few in number, La Cepede 

 having described only six species. They are natives of 

 warmer seas. They are covered with long and formi- 

 dable spines, like a hedgehog, and often exhibit a rich 

 variety of colours. The D. atinga, a native of the tro- 

 pical seas, is one of those fish considered by navigators 

 as noxious. According to Pison, the gall is so virulent 

 as to produce nearly instantaneous death in those that 

 eat the parts of the fish where any of it has been spilt. 

 The sound of the same fish, however, produces an isin- 

 glass, equal in quality to that which is obtained from 

 the Acipenser huso. 



GENUS XVIII. SPHEROIDES. 



Body globular, four teeth or more in the upper jaw, 

 no dorsal, anal or caudal fins. 



La Cepede formed this genus for the reception of a 

 species drawn by Plumier, and supposed to live in the 

 sea on the east coast of America, 



GENUS XIX. SYNONATHUS. Pipe-Fish. 



Head produced, mouth small and terminal, furnish- v_ii "^ 

 ed with a lid, no teeth ; gill-openings on the neck. Pipe-fish. 



The species of this genus have never been determined 

 in a satisfactory manner. Even the British species are 

 in confusion. There are eight species described, and 

 some varieties ; but it is probable that the characters of 

 the sexes have been hastily considered as marks of dis- 

 tinct species. 



It appears from the observations of naturalists, that 

 the species of this genus belong to the ovovivipa- 

 rous division of fishes, or those which hatch their eggs 

 internally. Their bodies are covered with osseous plates 

 like a coat of mail. 



ORDER XV. THORACIC. 



GENUS XX. CYCLOPTERUS. Sucker. 



Mouth furnished with sharp teeth ; ventral fins uni- Sucker. 

 ted ; between these there is an organ of adhesion. 



There are upwards of twelve species of this genus 

 known. They may be distributed into sections from 

 the union or separation of the caudal, dorsal and anal 

 fins. They inhabit the sea, but are occasionally found 

 in the mouths of large rivers. Their flesh is soft and 

 oily, and eagerly sought after by seals. ' Some of the 

 species, in a few hours after death, dissolve into a ho- 

 mogeneous gelatinous mass. 



GENUS XXI. LEPADOGASTER. 



Tentacula four before the eyes ; organs of adhesion 

 double. 



We are indebted to Gouan for a knowledge of the 

 only species of the genus, which he fonml in the Medi- 

 terranean. It has since been observed, in other seas, 

 by many naturalists. 



OHDER XVI. ABDOMINAL. 



G-ENUS XXII. MACKOIUNCHUS. 



Snout produced ; jaws furnished with teeth ; scales 

 on the body small. 



This genus was formed by La Cepede, and contains 

 one species discovered by Osbeck in his voyage to 

 China, and described by him. 



GENUS XXIII. PEGASUS. 



Snout produced ; jaws furnished with teeth ; body 

 covered with large osseous plates. 



The first notice of this genus was given by Ruyschius. 

 It now contains three species. These have the pectoral 

 fins uncommonly large, and are capable of supporting 

 themselves for some time in the atmosphere. They are 

 all of a diminutive size, and live in the seas of warm 

 climates. 



GENUS XXIV. CENTRISCUS. Trumpet-Fish. 



Jaws without taeth, snout produced ; body compres- Trumpet- 

 sed; ventral fins united. 



La Cepede describes three species belonging to this 

 genus, viz. C. scutatus, velitaris, and scolopax. 



SUB-CLASS II. OSSEOUS FISHES. 



All the osseous fishes have free branchite. With a Osseous 

 few exceptions, they are oviparous. They appear to Ushes - 



