2o\> FISHES. 



"We also form a distinct genus of 



Triodon, Cur., 



Triodons, whose upper jaw is divided as in the Tetraodons, and the lower 

 one single, as in the Piodons. An enormous dewlap, almost as long as 

 the body and twice as high, is supported before by a very large bone 

 which represents the pelvis, and approximates them to certain Balistes. 

 Their fins are those of a Diodon, their body is rough as in Tetraodon, 

 and the surface of their dewlap is covered with numerous, small, rough 

 crests, placed obliquely. 



T. bursarivs, Reinw. ; Triad, macroptere, Less, and Gain., Voy. 

 de Duper., Poiss. No. 4. Tbe only species known; it was disco- 

 vered in the Indian Ocean by M. lleinward. 



FAMILY II. 



SCEERODERMES. 



The second family of the Plectognathes is easily distinguished by a 

 conical or pyramidical snout, prolonged from the eyes and terminated by 

 a small mouth, armed with a few distinct teeth in each jaw. The skin is 

 usually rough, or invested with hard scales; the natatory bladder is oval, 

 large and strong. 



Balistes*, Lin. 



The Balistes have the body compressed; eight teeth in a single row in 

 each jaw, generally trenchant; the skin scaly or granulated, but not ex- 

 actly osseous; the first dorsal composed of one or more spines articulated 

 with a particular bone which is attached to the cranium, marked by a fur- 

 row into which they are received; the second dorsal long, soft, and placed 

 opposite to a nearly similar anal. Although the ventrals are wanting, a 

 true pelvic bone is observed in the skeleton suspended to the bones of the 

 shoulder. 



These fishes abound in the torrid zone, near rocks which rise to the 

 surface of the water, where they display their brilliant colours like the 

 Chaetodons. Their flesh, which is but lightly esteemed at all times, be- 

 comes, it is said, poisonous during the period in which they feed on the 

 coralline Polypi ; fucus is all that I met with in those I opened. 



Balistes, proper, 

 Have the entire body covered with very hard, large, rhomboidal scales, 



* Balistes, a name given to these fishes by Artedi, from I heir Italian appellation 

 Pesce halcstru, which is itself derived from ;> supposed similitude between the mo- 

 tion of their great dorsal spine and that of a cross-bow. 



