APPENDIX 



577 



Sa. 



9a. 



Cut away the roof of the cranium and expose the brain. 

 Note its regions and trace out the nerves. The ophthalmic 

 is the superficial one (Fig. 410). 



Cut through the auditory capsule. Note labyrinth, with large 

 otolith in vestibule. 



In skull, note the following bones : in cranium, basioccipital, 

 exoccipitals, supraoccipital, parietals, alisphenoids, frontals, 

 parasphenoid ; in auditory capsule of one side, epiotic, 

 pterotic, opisthotic, prootic, sphenotic ; in either orbit 

 lacrymal, suborbitals ; in nasal region, nasals, vomer, 

 mesethmoid, parethmoids ; in either upper jaw palatine, 



Fig. 411. — The skull of a cod, from the left side. — From Reynolds. 



t and 2, Lacrymal ; 3, median ethmoid ; 4, frontal ; 5, supraoccipital ; 6, pterotic ; 

 7, orbit ; immediately below is the parasphenoid ; 8, pterygoid ; 9, suborbital ; 

 10, bones of orbital ring ; n, maxilla ; 12, premaxilla ; 13, hyomandibular ; 

 t4, symplectic ; 15, quadrate; 16, metapterygoid ; 17, opercular; 18, sub- 

 opercular ; 19, preopercular ; 20, interopercular ; 21, articular ; 22, dentary. 



pterygoid, mesopterygoid, metapterygoid, quadrate, pre- 

 maxilla, maxilla ; in either lower jaw, articular, angular, 

 dentary ; in either hyoid arch, hyomandibular, symplectic, 

 epihyal, ceratohyal, hypohyals, urohyal, branchiostegal rays ; 

 in either operculum, opercular, preopercular, subopercular, 

 interopercular (Fig. 411). 



b. Note the parts of the vertebrae. 



i. In the shoulder girdle and fore-fin skeleton, note: post- 

 temporal, supraclavicle, clavicle (cleithrum), post-clavicle, 

 scapula, coracoid, brachial ossicles, fin rays (Fig. 412). 



a. In the pelvic girdle note that each half consists of a single 

 bone, in which iliac, ischial, and pubic regions are not 

 distinguishable. 



