70 PICIN^. 



on the back. This, however, is not peculiar to Woodpeckers. 

 The lateral processes of the caudal vertebrae are very large, so 

 as to prevent much lateral motion. In the accompanying 

 figure, which represents the sternum of Picus pileatus, the 



body is seen to have two notches on each side behind, a rather 

 low crest or ridge, which however is much prolonged anteriorly, 

 a slender furcula, of which the crura are extremely compressed, 

 and not widely separated, long coracoid bones, and scapulse 

 singularly curved downwards and enlarged at the end, in 

 which respect they differ from those of any birds known to me. 

 The humerus is large, and has a small bone in its articulation. 

 The metacarpus consists of two undivided bones ; there are, 

 besides the pollex, two digits, one of two phalanges, the other 

 of one. The pelvis is of moderate size. The femur also mode- 

 rate. There is a small patella. The tibia is rather stout, and 

 the fibula extends to half its length ; the tarsal bone is slender ; 

 the phalanges are two, three, four, and five, as usual ; the last 

 phalanx of each toe large, compressed, with a deep lateral 

 groove. 



As the Woodpeckers seem to be analogous to the Parrots, it 

 appears reasonable that they should form several genera, and, 

 accordingly, some authors, perhaps for the purpose of making or 

 finding the necessary number of groups for their circles, have con- 

 structed numerous subgenera, of which the characters are derived 

 from very slight differences in the form of the bill, and the length 



