126 



ELEMENTAL Y ANA TOMY. 



[LESS. 



appendages (termed branchiostegal rays} diverging from the 

 large cerato-hyals. 



The body of the hyoid is small in Fishes, and excessively 



FIG. 114. LEFT BRANCHIAL ARCHES OF PERCH. (After Cnvier.) 



i, glosso-hyal; 2, 3, and 4, basi-branchials ; 5, hypo-branchials ; 6, cerato-bran- 

 chials ; 7, epi-branchials ; 8, styliform pharyngo-branchial ; 9, pharyngo-bran- 

 chials ; 6"", inferior pharyngeal bone ; 9' and 9", superior pharyngeal bones ; 

 5, 6, 7, and 8, first branchial arch ; 5', 6', 7', and 9, second branchial arch ; 5", 

 6", 7", and g', third branchial arch ; 5", 6'", and 7'", fourth branchial arch ; 

 6"", fifth branchial arch. 



so when compared with the enormous increase in size and 

 complexity of the cornua and cornicula. 



FIG. 115. SIDE VIEW OF THE CARTILAGINOUS SKELETON OF THE HEAD OF 

 A SHARK. 



This shows the successive arches except the first pair, or irabeculce cranii, 



which form the base of the skull in front of the pituitary fossa. 

 pq, pterygo-palatine, or second arch ; w, mandibular, or third arch ; h, hyoidean, 

 or fourth arch (the corniculum, stylo-hyoid ligament, styloid process, &c., of 



sixth, seventh, eighth, and 



man). From behind it the branchiostegal rays are seen extending backward 

 6 to 65, the branchial arches forming the fifth, 

 ninth arches of the skull. 



( From the College of Surgeons' Museum. ) 



A glosso-hyal and a uro-hyal, however, may exist, as we 

 see in the Cod. 



