i TOMY OF FISH. 



155 



an incisioi the mediau veatral line from 1 I of the 



toral tin- 1" jusl bef >re I ind followii 



ity upward and foi ikiug 



not to injure the large Bwimmi i nor the fa 



in front. Now opeu tin ivity, which lies imm 



behind and below tb Cut away the i 



irouud the !>:u-k of the bead the brain, 



and remove the li lular tissu md the brain. If the 



of one sidt3 ai pay and the in - Irawn oul 



will appear very mucb as in F 



The cavity of the mouth wi behind the bran- 



chial chamber or pharynx, win nee we can pass u probe uu; 



Fie. 199.— Anatony . brain of the Cunn 

 olfactory lobea; the crura and the thalaini i 



[urn; If, medulla. 



hrough any of the gill-slits. There is a Bingle r 

 teeth in front on both the under and upp< - in the 



above and below there are rouuded teeth. Al lb the pharynx 



are the four gill-slits aud the four arches. Hie euti l slit 



is guarded iu front and behind by a row of proj 

 append d to the arch -. « I i the ou ihe 



fourth. isa double row of filaments, richly supplied with b 

 sels which, shining through, give a brilliant red color to the 

 the fourth arch there i< but a single ro \ . At the upper and | 

 comer of the pharynx is the small opening of the short ossopb 

 The branchial chamber has an upward extension on the 

 which lie the false gills (.ft), which are accessory respiratory i i 



