178 MR. F. E. BEDDARD ON THE CUCKOOS. [Feb. 17, 



the outer bifurcation of the ventral tract found in Geococcyx, &c. ; 

 this outer bifurcation is only three feathers lon^ in Piaya cayana \ 



The upper surface of the head is sparsely feathered; the spinal 

 tract is first continuous round the sides of the neck with the paired 

 ventral tract ; posteriorly it narrows, and at the level of the anterior 

 end of the scapula bifurcates into two slender branches, each composed 

 of only four feathers, arrang;ed as shown in the drawing (fig. 5, 

 p. 177); posteriorly there is a slight break between this portion of 

 the dorsal tract and the rest, which is considerably wider and is 

 continuous with the feathering on the upper surface of the thigh ; 

 about opposite the attachment of the femur the spinal tract of both 

 sides becomes fused and runs as a single tract closely feathered to the 

 base of the oil-gland. On the ventral surface of the uropygium are 

 two short tracts, one on either side, which unite behind the aperture 

 of the cloaca ; these are not continuous with the ventral tracts in 

 front, but with the dorsal tract and the feathering over the thigh. 



It will be clear from this description of the pterylosis that 

 Piaya cayana should be placed in the Cuculine division of the 

 family, and the structure of its syrinx is in harmony with this 

 arrangement. On referring to Nitszch, however, I find that Piaya 

 cayana (under the name of Coccygius cayanus) is placed in the same 

 group with Centropus, Crotophaga, &c. I cannot agree with this 

 systematization at all. In only one individual of Piaya cayana, 

 examined by myself, the inferior tract of either side showed a 

 faint trace of a bifurcation posteriorly, and though the comparatively 

 narrow inferior tract with its close feathering is rather different from 

 that of Cuculus, it is clearly with that genus rather than with 

 Geococcyx that Piaya cayana should be classified. 



Coccyzus americanus. — The ventral tract, as in Piaya cayana, is 

 double from just after its point of origin at the mandibular symphysis ; 

 the two halves, however, reunite before the junction of the head with 

 the neck, but very shortly after again become separate. The rest of 

 the ventral tract is so like that of Piaya that there is no need to 

 describe it ; I did not, however, find the rudimentary outer branch 

 indicated in the figure of Piaya, but as this part of the skin was 

 rather damaged, I cannot speak with certainty. The spinal tract is 

 like that of Piaya, but the break between the anterior and posterior 

 sections of the tract hardly exists. 



Saurothera dominicensis. — The inferior tract is double at its point 

 of origin close to the mandibular symphysis, as in Piaya cayana ; each 

 tract is here extremely narrow, two to three feathers wide, and is 

 separated from its fellow and from the edge of the mandible by 

 narrow spaces devoid of feathers, each of which is almost exactly of 

 the same width as the tract itself. 



At the junction of the head with the neck the inferior tract becomes 

 single, and the feathers have the chevron-like arrangement already 

 referred to in other genera ; about halfway down the neck the 



' I only noticed this in one specimen ; in others each pectoral tract was 

 quite single. 



