706 



ICHTHYOLOGY. 



Classifica- to enjoy an independent existence. Other eggs come 

 tion of forward to the same position ; and when all have been 



"t't-r' wcluded, the edges of the opening meet, and speedily 

 grow together, when a fresh rupture takes place in the 

 following season. This is a curious instance of the 

 ovoviviparous mode of reproduction. This species is 

 found both in the East and West Indies. 



GENUS CLXX. DORAS. 



Two dorsal fins ; the second adipose ; longitudinal 

 rows of large hard plates on the sides of the body. 



Two species; viz. D. carinatus and costatus belong 

 to this genus. They were formerly considered as 

 Siluri. The first of these is a native of Surinam ; 

 the second is common to America and India. Its 

 flesh is said to have a very unpleasant taste ; and the 

 formidable spines with which it is armed, are consider- 

 ed by the fishermen as venomous. For the purpose of 

 curing the wounds which they receive by accident 

 from this fish, they anoint them with the oil which 

 they obtain from its liver, a balm which they frequently 

 carry about with them. 



GENUS CLXXI. POGONATHUS. 



Dorsal fins two in number, supported by rays ; body 

 with lateral plates. 



This genus differs from the former, in the second 

 dorsal fin being radiated. It contains two species, first 

 observed by Commerson. The first named P. cow- 

 bina, a native of Plate river, has twenty-four filaments 

 in the beard of the under jaw. It grows to the length of 

 more than two feet, and weighs upwards of six pounds, 

 but its flesh is soft and insipid. The P. auratus has only 

 one filament in the beard on the under jaw. 



GENUS CLXXII. CATAPHRACTUS. 



Two dorsal fins ; the second with one ray ; body with 

 lateral plates. 



We owe this genus to Bloch. It contains three spe- 

 cies. The first of these, named C. callichthys, is found 

 both in the East and West Indies. It lives in limpid 

 running fresh water, and is said to creep out of the wa- 

 ter to a considerable distance from the rivers, and to 

 dig holes in the ground, in which it conceals itself. It 

 seldom exceeds a foot in length. Its flesh is said to be 

 palatable. It has four filaments in the beard, and the tail 

 is rounded. TheC. Americanus has six filaments in the 

 beard, and has hitherto been observed only in Carolina. 

 The C. punctatus has four filaments in the beard, and 

 the tail is in the form of a crescent. It is found in the 

 rivers of Surinam. 



GENUS CLXXIII. PLOTOSUS. 



Two dorsal fins ; the second of these, and the anal 

 fin, united with the caudal. 



The P anguillaris is the only known species, and is 

 a native of the Indian seas. It was inserted by Bloch 

 in his genus l'la/y;~lachut. 



GENUS CLXXIV. AGENEIOSUS. 



Two dorsal fins; the second adipose; chin beard- 

 less. 



The two species, A. armatus and inermis, are natives 

 of the Indian and South American seas, and were for- 

 merly included among the Siluri. The first of these 

 has a remarkable long serrated bony process on each 

 side of the head near the nostrils. 



GENUS CLXXV. MACUOMPHOSUS. 

 Mouth beardless; first ray of the first dorsal fin 

 lengthened; strong and notched; second dorsal fin 

 supported by rays. 



The Silurus cornutus of Gmelin, is the only known 

 1 



species of the genus. It was first described by For- Classifies. 

 skael. The snout is about half the length of the body, 'I'. 1 " of 

 compressed, and a little recurved at the top. The first ^J^ 5 *"*^ 

 ray of the first dorsal fin is serrated beneath for about 

 half its length, and extends nearly to the tail. This fin 

 contains nine rays, the second dorsal fin contains only 

 six. 



GENUS CLXXVI. CENRTANODON. 



Head depressed, and covered with large hard plates ; 

 mouth at the extremity of the snout, without teeth or 

 beard ; one or more spines on each gill lid. 



This genus contains only one species, formerly term- 

 ed Silurus imberbis. It was first described by Hout- 

 tuyn, and is a native of Japan. The body and tail are 

 lengthened, and covered with distinct scales. The eyes 

 are large and approaching. 



GENUS CLXXVII. LORICARIA. 



Body covered with a coat of mail ; mouth inferior ; 

 lips extensile ; one dorsal fin. 



The genus contains two species, viz. L. setifera, and 

 maculata, natives of the American seas. The mouth 

 of the first is surrounded by a number of small fila- 

 ments, which are not observable on the latter. These 

 fish bear a very close resemblance to the sturgeon in the 

 armature of the body, the position of the mouth, and 

 the great size to which they attain. 



GENUS CLXX VIII. HYPOSTOMUS. 



Body covered with a coat of mail ; mouth inferior ; 

 lips extensile ; two dorsal fins. 



The presence of the second dorsal fin, is the charac- 

 ter by which this genus is distinguished from the pre- 

 ceding. The only known species is the H. guacari of 

 Lacepede, n native of the American rivers. It is the 

 Loricaria plecostomus of Linna>us. The flesh is said 

 to be good. 



GENUS CLXXIX. CORYDORAS. 



Body and tail covered on the sides with large plates ; 

 mouth terminal ; no beard : two dorsal fins, with more 

 than one ray in each. 



A specimen of the C. Geoffroy, the only known spe- 

 cies, was found in the Dutch collection. Its native 

 country is unknown. In the first dorsal fin, there are 

 two spinous and nine articulated rays. The tail is 

 forked. 



GENUS CLXXX. TACHYSURUS. 



Mouth terminal, bearded ; the first ray of the dorsal 

 and pectoral fins strong ; dorsal fins two, radiated. 



The existence of the T. sinensis, the only known spe- 

 cies, rests on the authority of a Chinese drawing in the 

 Dutch collection. 



GENUS CLXXXI. SALMO. Salmon. 



Mouth terminal ; head compressd ; second dorsal Salmon, 

 fin adipose ; first dorsal fin as near the head as the 

 ventral fins ; upwards of four rays in the gill-flap ; teeth 

 strong and numerous. 



The characters of the twenty-nine species which com- 

 pose this important and extensive genus, have not been 

 satisfactorily determined. Naturalists, in general, at- 

 tending to the characters furnished by colour and by 

 the number of rays in the fins, have, we fear, multi- 

 plied the species unnecessarily. At present, indeed, it 

 is difficult from the characters in ordinary use, to de- 

 termine the young animals as of the same species with 

 the old. Recourse must be had to the characters fur- 

 nished by the organs of respiration, and the intestines; 

 and under the guidance of the marks which they 

 furnish, the species may be satisfactorily determined. 



