186 NOTES ON THE SALMO SALAR SPECIMEN — MORROW. 



the two nearly circular bones which represent the radius and ulna. 

 The anterior extremity of the coracoid is somewhat twisted, that 

 is, its inner and superior edge rises for its union by cartilage with 

 the clavicle, which sends out from its central ridge a flat process 

 for this purpose. 



The Humerus, 

 If you will look at the under side of the coracoid bone, which 

 on this aspect appears to be nearly flat and somewhat curved? 

 from its posterior extremity to its junction with the clavicle; 

 between the foramina already noticed you will perceive a central 

 ridge, which expands towards its posterior extremity ; about 

 midwa} 7 of its length there appears to be a transverse joining, or 

 symphysis, and following this ridge posteriorly you will see that 

 one edge of it forms the outer side of the inner foramen, and that 

 there is a line or indentation which passes by the edge of the 

 outer foramen to the transverse division from whence we started, 

 this appears to me to be, without doubt, the humerus, but to be 

 positive on this point requires the examination of very young 

 specimens of the salmon, which I regret to say my sight will not 

 permit me to undertake. 



Carpal Bones and Pectoral Fin. 



The pectoral fin is attached to four ossicles, or carpal bones, 

 with the exception of the upper or long ray, which is directly 

 articulated with the radius — the upper one of these ossicles and 

 the shortest is attached to the ulna ; the three lower to the pos- 

 terior extremity of the coracoid, at the lower part of the bone 

 which I regard as the humerus — all cartilaginously. The lower 

 ossicle is f , the upper about ^ of an inch in length. 



The rays of the pectoral fin are fourteen in number. The 

 first or upper ray is in length, from attachment to posterior 

 extremity or point, 4| inches, the others gradually decreasing in 

 length until the lowest and shortest is If inches. Looking 

 at the fin on either side the rays are crowded, and set one 

 within the other after the manner of a Venetian blind when 

 turned to keep out the rays of the sun, the inner inferior margin 

 being the lowest. The upper or long ray, at its attached extre- 

 mity is very much stronger than the others, and at this point it 



