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bulletin: museum of comparative zoology. 



carpal bone ; digits i^ and ii are of nearly equal size, each composed of 

 three phalanges and borne on a single large metacarpal, i" and i* are 

 enclosed in the same hoof, which shows evidence of duplication. 



The phalanges of digit ii are of normal size and form ; the carpals 

 are practically normal, but the trapezium articulates with the proximal 



n. m. 



Fig. V. — Posterior view of left polydactyle inaiius, showinp; innervation, i", i*", 

 supernumerary dij^its; n. m., median nerve; 1, first branch of median nerve supplj'ing 

 digits I" and i". i natural size. 



end of the compound metacarpal, and ends in a free distal process. 

 The musculature of digit ii is normal. The extensor proprius pollicis 

 et indicis divides and is inserted into the distal phalanges of both i" and 

 1*. The flexor perforans gives off an independent tendon to digit i^. 

 The innervation of the raanus (Fig. V) is identical with that of cases 

 in which the two extra digits are entirely distinct from ii (Fig. Q). 



