3<58 



MANUAL OF ZOOLOGY. 



in the form oi fins — that is, of expansions of the integuroeni' 

 strengthened by bony or cartilaginous fin-rays. The anterioi 

 hmbs are known as the pectoral fins, and the posterior as the 

 ventral fins ; and they are at once distinguished from the so- 

 called "median" fins by being always symmetrically disposed 

 in pairs. Hence they are often spoken of as the paired fins. 

 The scapular arch (figs. 135, 136) supporting the pectoral 



Fig. 136. --Pectoral hmbs of Fishes (after Owen). A, Cod (Morrhmi vulgariiw B 

 Angler (Lophtus). ss Supra-scapula ; i Scapula ; co Coracoid ; r Radius ; v Ulna 

 cc t^rpal hones; / Fin-rays, representing the metacarpus and phalanges of the 



limbs is usually joined to the skull (occipital bone), and con- 

 sists of the following pieces on each side: — i. The supra- 

 scapula {ss) ; 2. The scapula (j), articulating with the former ; 

 and, 3. The coracoid {co), attached above with the scapula, and 

 united below, by ligament or suture, with the coracoid of the 

 opposite side, thus completing the pectoral arch. Lastly, there 



