43 Dcscyiption of a iiew Genus of Fish named Polypiera. 



duals. Having found that all the fish of the Nile arc di- 

 vided bv travellers into two classes : that some during the 

 decrease of the river ascend from its mouth, and that others 

 descend from Nubia at the time of the inundation, I was 

 desirous of kuowiag to w hich of these divisions the hich'tr 

 belonged : but I never met with any person who could in- 

 form me. All that I was able to gather from the informa- 

 tion I obtained was, that tlie hkh'tr fretjuents only the 

 deepest parts of the river; it lives constantly in the mud; 

 and that, abandoning its retreats only in the spawning sea- 

 eon, it is then sometimes caught in the fishermen's nets. 

 I have not learned on what it feeds. I opened and dissected 

 tlirec individuals, but their stomachs were entirely empty. 

 V>\- the extent of its mouth, however, the numerous teeih 

 with which it is armed, and the conformation of the in- 

 testinal canal, there is reason to believe that it is carnivo- 

 rous. Its rtesh is white, and nmeh more savoury than that 

 of the other inhabitants of the Nile. As it is proof against 

 the attacks of a knife, it must be boiled : the skin is then 

 more easily detached, and may be removed in one piece. 



VIII. Katiiral Reluitons. — The genus to wliieh the hickir 

 approaches most is that of the esorcs : it has even some rc- 

 !<emblancc to the cayman and scaly eel ; a resemblance for 

 which it is indebted to its integuments, and the distribution 

 and size of its scales. But it mav be readily conceived that 

 this is not a consideration of sufficient importance to induce 

 us to class it among the erofo.i-, since it differs from them, as 

 well as from the other known abdominal fishes, by organs 

 much more essential. It is the only one of this order which 

 has its fins placed at the extremity of the arm, the only 

 one in which the place of the branchio-stege radii is supplied 

 bv an osseous plate ; the only one which has a kind of air- 

 holes furnished with valves to shut these apertures out- 

 wardlv : all characters by which it approaches the cetacea : 

 it is also the only one in which the dorsal line is iurnished 

 throughout its whole length with small fins ; in which the 

 first radius of these fins is transformed into a dart with two 

 points ; in which the apophyses of the vertebrie support 

 inmiediatelv the osseous radii of the dorsal fins ; which has 

 a tail so short that it is almost useless for natation ; and 

 which, in regard to the organs of digestion, seems to esta- 

 blisii a shade between the abdominal and cartilaginous fishes., 

 From these considerations I think ujyselt" authorized to de- 

 termine, that as the bkhir cannot be admitted into any of 

 the known div'sions, it ought to be considered as an insu^ 

 !ated bcingj and in that state of anomaly which ntituralists 



usually 



