CBLETODONTOIDE.E. 73 



CH^ETODONTOIDE^.— SQ TJAMMIPENNM. 



The fish composing this family are recognisable, at first sight, by the articulated, 

 and often the spinous portions of their dorsal and anal fins being thickly enveloped in 

 scales, and uniting so gradually with the compressed body that the line of junction 

 becomes almost imperceptible *. Their intestines are pretty long and the cseca 

 numerous. They are divided into three tribes. In the first, comprising the Chce- 

 todontes of Linnaeus, the long, slender, flexible teeth are disposed in several 

 crowded rows on the jaws, like the hairs of a brush ; the mouth is small ; the 

 palate and tongue are toothless ; the gill-opening moderately cleft ; and its mem- 

 brane supported by six rays only. This tribe forms a very natural group offish, 

 many of which exhibit the most varied and brilliant colours, being, in this respect, 

 not in the least inferior to the most gay and shining of the feathered tribes. The 

 presence or absence of a preopercular spine ; the form of the dorsal, whether entire, 

 notched, or double, the extent to which it is scaly, and the elongation of its spines by 

 filaments ; the number of anal spines ; the form of the body ; the size of its scales ; 

 the form of the muzzle ; protuberances on the head, and some other varieties of 

 structure, furnish characters by which the genera that enter into this tribe are dis- 

 tinguished from each other. The genus Platax has a row of cutting teeth 

 exterior to the bristle-like ones, Psettus has teeth like the pile of shorn velvet, 

 and both these genera have the toothless palate of the rest of the tribe. The second 

 tribe contains two genera with cutting teeth in the jaws, viz., Pimilepterus, which 

 has the incisors in a single row, with cutting edges rising vertically from horizontal 

 bases that project backwards and fix them to the jaw : a stripe of velvet-like teeth 

 behind, and also some asperities on the vomer and palate ; and Dipterodon, of which 

 the only one species that is known has teeth like those of the Sparoid genus Sargus : 

 its vomer and palate are smooth. The third tribe is characterised by the presence 

 of vomerine and palatine teeth, and by teeth in shorn velvet, or cardlike bands on 

 the jaws. Scorpis, enumerated in this tribe by Cuvier, has a row of strong, cylin- 

 drical teeth exterior to those in a velvet-like stripe, and is, in many characters, 

 similar to Platax, from which it is separated by the presence of palatine teeth. 



* Some of the Scicenoidece, the Nebres, Lepipteri. and Eqitiles, for instance, have fins much like those of the Chceto- 

 dontoidece, but they have not fine, flexible, bristle-like teeth, and in general they have a protuberant snout and cavernous 

 cranium. The Hctmulona have also scaly fins, but they are not so thick at the base as to look like a part of the body, so 

 that the general aspect of the fish is very different. 



