J93 



HYDROCYON, 



The genus Hydrocyon seems to exist in consider- 

 able abundance in many of the rivers, though few 

 specimens were procured in Guiana;* and in the 

 Brazilian fishes, Raphiodon of Agassiz takes its 

 place. He has characterised it, 



" RAPHIODON, Agassiz. Caput parvum, compressissimnm. 

 Oculi magni laterales. Os maximum oblique desoen- 

 dens. Dentes validissimi, acutissime, cum minoribus 

 alternantes, in ossibus intermaxillaribus minoribus mar- 

 ginem tantum anteriorem maxillae superioris confor- 

 mantibus, et in mandibula ; ossa maxillaria superiora 

 longa, angusta. Lateralia dentibus minoribus obsita. 

 Lingua magna, prominens, apice libera. Apertura 

 branchialis maxima. Membrana branchiostega radiis 4 

 gracilibus. Caput elongatum, compressum, squamis 

 parvis abductum ; abdomen acute carinatum sed non 

 serratum. Pinnae pectorales magna?, ventrales parvae, 

 analis latissima." 



Both the specimens which are figured (but under 

 the name of Cyonodon (have very strongly armed 

 jaws and a wide mouth ; the ventrals very small ; 

 while the anal fin covers more than a third of the 

 lower line of the fish. In many of these we have 

 some dark spot or other marking, as we have seen 

 so frequently among the fishes from those parts of 

 South America. 



* See Vol. I. p. 227. 



