2l6 



Corres^poiidence. 



[April 



Figure 4. — Ventral view of a plucked specimen of the Red-naped Woodpecker 

 (Sphyrapkus v. nuchalis) , showing its pterylosis. From nature, life size, by the author. 



cially the 'ventral tract' and its peculiar external branch (Fig. 3, m. and «). 



It will be seen that in Dryobates the main ventral tract is very broad 



near the summit of the shoulder, and continues to be so until we arrive at 



the bifurcation with its external branch ;«, which latter curves out towards 



