REPORT ON THE SPHENISCID^. 95 



2. Extensor metacarjyi radialis brevis. 



Le radial grele, Vicq d'Azyr, 1773, p. 574, Xo. 2. 

 Dfii- vordere Handanleger, Merrem, p. 157, No. 4. 

 Der Hiilfsmuskel des Mittelhandstreckers, Wiedemann, p. 92. 

 Extensor metacarpi radialis hrevis, Tiedemann, p. 318, No. 2. 

 Extensor wetacarin radialis brevis, Heusinger, p. 187, No. 23. 

 Le court extenseur radial, Meckel, vol. vi. p. 56, No. 2. 

 Extensor metacarpi radialis hrevis, Schoepss, p. 148, No. 32. 

 Extensor pollicis lonrjus, Selenka, vol. vi. p. 133, No. 63. 

 Abdv^teur du pouce, Gervais and Alix, p. 27. 



Attachments. — This muscle arises from the upper third of the contiguous borders of 

 the radius and ulna, as well as from the middle third of the outer surface of the former. 

 The muscle ends on a tendon which lies at first in an oblique groove on the outer 

 surface of the lower end of the radius, and after crossing the wrist joint is inserted into 

 the radial margin of the upper end of the radial metacarpal bone, close to the insertion of 

 the extensor radialis longus. 



Action. — The muscle extends the hand at the wrist joint. 



Relations. — It rests upon the outer surface of the radius, and is concealed by the alar 

 aponeurosis. 



Variations. — In two out of three specimens of Aptenodytes longirostris which I 

 dissected, this muscle was absent. In the third it agreed with the description above 

 given. 



3. Extensor carpi idnaris. 



Le long flechisseur du metacarpe, Vicq d'Azyr, 1773, p. 575, No. 5. 



Cuhital externe, Cuvier, vol. i. p. 520. 



Der Idntere innere Handspanner, Merrem, p. 156, No. 3. 



Der ohere oder lange Mittelhandheuger, Wiedemann, p. 91. 



Flexor metacarpi radialis, Tiedemann, p. 319, No. 4. 



Der Speichen-Mittelhandheuger, Heusinger, p. 188, No. 25. 



L'extenseur cubital de la main, Meckel, vol. vi. p. 57, No. 3. 



Abductor metacarpi, Schoepss, p. 150, No. 33. 



Extensor carpi ulnaris, Selenka, vol. vi. p. 131, No. 60. 



Ze cubital posterieur, Gervais and AHx, p. 27. 



Attachments. — The extensor carpi ulnaris in the various species of Penguin is entirely 

 tendinous. It arises above, from the outer side of the lower end of the humerus imme- 

 diately behind the attachment to that bone of the external lateral ligament of the elbow 

 joint. It extends along the interval between the radius and ulna, and, after crossing the 

 outer side of the wrist joint, is inserted into the middle in length of the ulnar margin of 

 the radial metacarpal bone. 



