THE COD. 131 



75- The brachial ossicles, four small, dice-box 

 shaped bones, articulating with the posterior border of the 

 scapula and coracoid. 



76. The fin-rays, attached to the distal ends of the 

 brachial ossicles and having essentially the same character 

 as those of the median fins ; they diminish gradually in size 

 from the pre-axial to the post-axial border of the fin (see 

 § 95 ) overlap one another at their proximal ends, and are 

 much frayed out at their distal extremities. 



XV. In the hip-girdle and pelvic fins note 



77. The pelvis, consisting of the two thin, irregular 

 innominate bones,' united with one another in the middle 

 ventral line, but showing no distinction into the three 

 ossifications of the typical vertebrate os innominatum. 



78. The fin-rays, articulating with the postero-external 

 borders of the innominate bones. Owing to the position 

 of the pelvic girdle beneath the throat, the pelvic fins come 

 to be situated anterior to the pectorals. 



B.— DIRECTIONS FOR DISSECTION. 



XVI. Make out the following external characters : — 



79. The elongated body (Fig. 30), slightly compressed 

 from side to side ; the head passing insensibly into the 

 trunk, and the trunk into the tail. 



80. The integument, containing numerous small 

 imbricating scales, covered with a layer of thin, slimy, 

 pigmented epiderm, the colour of which varies in differ- 

 ent parts of the body, being white below, and greyish or 

 olive, mottled with golden yellow, above. 



1 It is possible that the so-called innominate bone may represent the 

 basale metapterygii or basipterygium of the Elasmobranch fin (p. 40, 

 § 52), and not a true pelvic girdle. 



