436 FISHES. 



DIAGRAM XXVII. 



Teleosteans. 



The uppermost figure shews the familiar shape of the haddock. Na. 

 nasal apertures ; Pelv. pelvic fin ; Pecf. pectoral fin. The unpaired fiins 

 and the muscle segments are also shewn. 



The figure named Circ. (after Nuhn), shews the heart with the sinus 

 venosus (s. v.), the auricle {A.), the bulbus asteriosus (B. a.) in front of 

 the ventricle ; the ventral aorta giving off afferent branchials (a. b. ) ; the 

 efferent branchials {fff. b. ) ; the carotids {fa. ) rising from the cephalic 

 circle in front ; the aortic trunks (a) uniting in the dorsal aorta (</. a.) ; 

 the cardinal venus {card. ) bringing back impure blood to the heart. 



The Gill-filament (after Nuhn) shews the two currents of blood — the 

 venous vessels (solid black), the arterial vessels (interrupted lines). 



The figure Limb (from Gegenbaur) shews the pectoral fin ; d. the 

 clavicle ; sc. the scapula ; cor. the coracoid ; b. p. the basal pieces ; r. 

 the fin-rays ; p. cl. the post-clavicle ; s, cl. the supra-clavicle ; p. t. the 

 post-temporal. 



The Ceratodus fin (after Giinther) is an archipterygium with a central 

 axis bearing lateral fin-rays. 



