PEECID^. 



379 



It lias been recommended for acclimatisation in England, and 

 there is no doubt that in certain localities it might prove a 

 valuable addition to the native fauna ; but like aU its con- 

 geners it is very voracious and destructive to smaller fishes. 

 Two other species inhabit rivers of European and Asiatic 

 Eussia, and two or three the fresh waters of North America. 



PiLEOMA. — All the teeth minute, vihiform, without canines ; 

 teeth on the vomer and palatine bones. Two dorsal fins — the 

 first with fourteen or fifteen spines. Body rather elongate, with 

 small scales. Prseoperculum not serrated. 



Small freshwater perches abundant in the United States. 

 Like the following genus, and some others which need not 

 be mentioned here, they can be regarded as small, dwarfed 

 representatives of the preceding genera. The species seem 

 to be numerous, but have not yet been sufficiently well dis- 

 tinguished. The latest and best account of them is by L. 

 Vaillant, "Eecherches sur les Poissons d'eaux donees de 

 I'Am^rique septentrionale {Mheostomatido})," in Nouv. Archiv. 

 du Mus(^um d'Hist. Nat. de Paris, ix., 1873. 



BoLBOSOMA. — Allied to Pileoma, but with only nine or ten 

 feeble spines in the first dorsal fin. North America. 



AsPEO. — ^Body elongate, cylindrical ; snout thick, projecting 

 beyond the mouth, which is situated at its lower side. All the 

 teeth villiform, without canines ; teeth on the vomer and palatine 

 bones. Two separate dorsals. Praeoperculum serrated; prse- 

 orbital entire. Scales small. 



Two small Perches from the Danube and some other 

 rivers of the continent of Europe, Aspro vulgaris and A. 

 zingel. 



Centropomds. — Body oblong, compressed, with scales of mode- 

 rate size. All the teeth vilhform, without canines ; teeth on the 

 vomer and palatine bones. Two dorsal fins, the first with eight 

 strong spines, the anal with three, the second of which is very 

 strong and long. Prseoperculum with a double denticulated edge. 



