1 46 ZOOTOMY. 



extending from the basi-hyal at first outwards and forwards, 

 and then, almost immediately, outwards and backwards, 

 curving round the gullet, and finally coming in close 

 contact with the ventral surface of the auditory capsule. 

 The short ventral portion of the anterior cornu is the 

 hypo-hyal, the next considerably expanded portion is 

 distinguished as the cerato-hyal, the dorsal slender part 

 is the stylo-hyal. 



81. The middle cornua (m.co), paired rods springing 

 from the basi-hyal just posterior to the anterior cornua, to 

 which they run more or less parallel : the proximal ends are 

 ossified. The middle cornua represent the first branchial 

 arch. 



82. The posterior cornua (p.co\ paired cartilaginous 

 rods, springing from the posterior edge of the basi-hyal, and 

 passing backward and slightly outwards : they represent the 

 hypo-branchial region of the second branchial arch (see 

 description of the skate's branchial arches p. 38, 41). 



83. A small curved cartilaginous rod attached by fibre to 

 the dorsal end of each middle cornu : it probably represents 

 the dorsal or epibranchial region of the second branchial 

 arch. 



IX. In the shoulder-girdle note 



84. The coracoids (see dotted outline in Fig. 39), flat 

 paired bones articulating with the an tero- lateral edge of the 

 sternum : each furnishes the central half of the glenoid 

 cavity for the articulation of the humerus, and is divided 

 by a large fenestra into an anterior bar, the precoracoid, 

 and a posterior portion, the coracoid proper. 



85. The scapulae, articulating each with the outer 

 extremity of the corresponding coracoid, and forming the 

 dorsal half of the glenoid cavity. 



86. The suprascapulae, continuous with the expanded 



