278 



COMPARATIVE ANATOMY". 



Fie. 222. HKAUT.S UK YAUIUI'.S FISHK.S A, OK IIIK HAMMER-HEADED SIIAKK 

 (Zii<l:nn nirtllcitx) B, OF Sili'ntx </?"// i'.s; C, UK A SELACHIAN, CUTOI'K.N. 



In A and B, A, A, atria ; a, a (in A), auricular appendages ; V, ventricle ; Ha, bulbils 



arteriosu.s ; tr, ventral aorta. 

 In C, a, a, indicate the atrio-VPntricular valves, and I, the valves in the conns 



arteriosns (fJa) : A, atrium ; V, vrntiii ]<. 



ventricle (Fig 1 . 222, V) ;iud an atrium (A), the latter receiving 

 its blood from a sinus venosus, .-nnl lu-ing laterally expanded 

 to form the appendices auricula' (A, , }. 



