FISHES 
FAMILY OF PERCIDE. . 
Genus PERCICHTHYS, Girard. Kill 
Gen. car. Body oblong or elongated, compressed, covered with scales of medium develop- ; : 
ment, finely ciliated upon their posterior margin. Snout rather thick and blunt, overlappins . 
slightly the lower jaw. Two dorsal fins contiguous at their base. Insertion of ventral fins 


















immediately beneath the base of pectorals. Anal fin provided with three spiny rays. Tong 
smooth. Upper surface of head, suborbitals and posterior dilatation of maxillary, covered witl 
scales, as well as the cheeks and opercular apparatus. Suborbital and preopercle steel 
Opercle provided with a spine. Branchiostegals six or seven in number. Card-like teeth, ae 
the jaws; velvet-like teeth disposed upon a transverse band in front of the vomer and upon a anar-— 
row band along the palatines, sometimes only towards the anterior extremity of the latter bones. — . 
Syv. Percichthys, Grp. Proc. Acad. Nat. Sc. Philad. VII, 1854, 197. 
Oxs. This genus, closely allied to Perca, is to be dis inguished from it by the shape of the | 
snout and the structure of the mouth; the presence of small scales on the top of the head, on re 
the suborbital bones and (upper) asses + ; the position of the ventral fins, and by the pres-— 
ence of three spiny rays, instead of two, at the anterior margin of the anal fin. Moreover, the i 
head, as a whole, has something of a sciznoid touch about it. aa 
Perea trucha, of Cuv. and Val.* which, according to M. d’Orbigny, is an inhabitant of 
the Rio Negro of Patagonia, is a species of this genus. eg 
I am led to consider Perca ciliata, K. and V. H., from the island of Java, Perca marginata, — 
Cuy. and Val., brought to France from the puseel hemisphere by the navigator Péron, and 
Perca trulta, One and Val., from Cook’s straight (New Zealand), as repeals referable to the 
genus Percichthys. oo 
Should this be true, the hitherto cosmopolite genus Perca would thus be restricted to ae ; 
boreal hemisphere; the analogous species of the ee hemisphere constituting an allied genus — 
or several allied genera, since one of the species of this group has led us to the establishment of — 
another genus equally distinct from both Perca and Pon cichthys. 
Perca levis, Jen.,f an inhabitant of the Rio Santa Crux, Patagonia, belongs also to sie rs 
genus Percichthys, being closely allied to P. trucha, if at all distinct from it. 
The following is the formula of its fins and branchiostegals: 
Br. 7; D.9—1/11; A. 3/9; C. 17; P. 15; V. 1/5. 
Again, Perca trucha of Cuv. and Val. is not identical with the Perca trucha of the “ Hist 
de Chile.’’ The latter we propose to call Percichthys chilensis. The distinctive marks ae 
* Histoire Naturelle des Poissons. Tome IX, 1833, 429. 
t Zool. of Beagle, IV. Fish, 1842, I, Pl. i. ie 
