670 DR. p. CHALMERS MITCHELL ON THE 



tendon which is inserted to the postglenoid scapula between the 

 two parts of the sub-coraco-scapularis, its insertion being quite- 

 covered by the outer part of that. "^ 



Serratits sttj)erjicialis 2^oste7'ior. — From the first two uncinate 

 processes and area of their ribs in line with them to about three- 

 quarters of an inch of the posterior inferior border of the scapula ; 

 covered .by the third portion of the serratus superficialis. 



Serratus superficialis metajjatagialis . — Origin from the same 

 two ribs as the ser. sujDer. posterior, but entirely from below the 

 uncinate processes, and reaching down almost to the sternum. 

 Insertion to the metapatagium, with a strong tendinous slip to 

 the tip of the scapula. 



The first of the three serrati, according to Furbringer, is very 

 variable even within families. The second is constant in many 

 families, variable in others. The limitation of the origin ta 

 dorsal of the uncinates is somewhat rare but has been noted in 

 Phoe'iiicopterus . The insertion of the serratus metapat. partly to 

 the scapula appears to be extremely rare. Fiirbringer has noted 

 it in Crex, where the condition is much as I find it to be in 

 Balceniceps, and in Fulmartis and Bucorvics, where the scapular 

 insertion alone occurs. The relation to the scapula is probably a 

 vestige of the origin of this muscle as a separated portion of the 

 serratus superfic. posterior. 



Serrcdus profundus. — From the last two cervical and first two 

 dorsal ribs to the scapula in four digitations. According to 

 Furbringer, this arrangement is normal in Herodii. 



Biceps hracMi. — This arises by a flat narrow tendon from the 

 acrocoracoid (text-fig. 128, B. 1, p. 675), alongside but not covered 

 by the origin of the coracobrachialis externus and separated by 

 that muscle from the tendon of insertion of the supi-acoracoideus 

 (pectoralis secundus). It passes under the insertions of the 

 pectoralis major without being connected with them, and passing 

 into a rounded belly (text-fig. 128, B. 2) runs down parallel with 

 the humerus to be inserted to a knob on the ulnar face of the 

 radius (text-fig. 127, Bi., 1, p. 672). It is then continued across 

 to the opposite face of the ulna (text-fig. 127, 4, 5) by a deep 

 broad tendon and a narrow more superficial tendon, first sending 

 a strong slip (text-fig. 127, 2) to the radial end of a radio-ulnar 

 ligament. 



The biceps obviously presents a highly specialized condition in 

 Balceiiiceps, the specialization consisting of the complete loss of 

 the usual humeral head. The two divisions are well separated 

 at their origin, and the radial and ulnar tendons of insertion 

 separate rather high up in most Steganopods, Storks and Herons. 

 As Fiirbringer has pointed out, the humeral head in such cases 

 can be traced to the radial insertion. As both radial and ulnar 

 insertions are well marked, indeed rather unusually complex in 

 Balcenice^is, I infer that the loss of the humeral head is com- 

 paratively recent. 



BicejJs patagialis. — This slip to the patagial tendons is absent 



