PEECID^. 375 



greater portion of the lack ; spinous dorsal vjell developed, gener- 

 ally with stiff spines, of moderate extent, rather longer than, or 

 as long as, the soft ; the soft anal similar to the soft dorsal, of 

 moderate extent or rather short. Ve^iitrals thoraeic, vnth one 

 spine and toith four or five rays. 



First Family — Percid.e, 



The seales extend hut rarely over the vertical fins, and the 

 lateral line is generally present, continuous from the head to the 

 caudcd fin. All the teeth simple and conical ; no harhels. No 

 hony stay for the prccopcrculum. 



A large family, represented by numerous genera and species 

 in fresh waters, and on all tlie coasts of the temperate and 

 tropical regions. CarnivoroiLS. 



Fossil Percoids abound in some formations, for instance, 

 at Monte Bolca, where species of Labrax, Lates, Smerdis and 

 Cyclopoma (both extinct). Bides, Serramis, Apogon, Therapon, 

 and Pristipoma have been recognised. Parapcrca is a genus 

 recently discovered in the Maries of Aix-en-Provence. A 

 species of Perca is known from the freshwater deposit of 

 Oeningen. 



Perca. — All the teeth are vilhform, without canines ; teeth 

 on the palatine hones and vomer ; tongue toothless. Two dorsal 

 fins, the first with thirteen or fourteen spines ; anal fin with two 

 spines. Prseoperculura and ]3r?eorhital serrated. Scales small ; 

 head naked above. Branchiostegals seven. Vertebroe more than 

 twenty-four. 



The "Freshwater Perch" {Perca fiuviatilis) is too familiarly 

 known to require description. It is generally distributed 

 over Europe and Northern Asia; and ecpially common in 

 North America, there being no sufficient ground for separat- 

 ing specifically the specimens of the Western Hemisphere. 

 It frequents especially still waters, and sometimes descends 

 into brackish water. Its weidit does not seem to exceed 



