1916] Chandler: Structure of Feathers 363 
nulum with 5 or 6 rather small hooklets, a series of short, curved 
ventral cilia, more slender in Pteroclis, and in the imner vane a 
series of small, spinelike dorsal cilia, the proximal ones of which 
are especially modified only in Gowra. 
(4) Proximal barbules of inner vane of remiges with short, stout 
base, moderate, pointed ventral teeth, and very slender pennulum, 
shorter than base. 
(5) Proximals of outer vane, towards tip of shaft, with ventral 
teeth becoming somewhat cilia-like in form, but a well-formed series 
of ventral cilia never developed. 
(6) Structure of coverts, scapulars, and back feathers much 
like that of outer vane of remex, except that hooklets of distal 
barbules frequently have prongs or spines on the edge nearer the 
tip of the barbule ; Pteroclis differs in having distal barbules of scapu- 
lars with more specialized barbicels than in remex. 
(7) Breast feathers with similar structure,-but pennula very 
elongated, no flexules ever developed. 
(8) Down barbules in Pteroclis and Gowra moderately long, 
without enlarged nodes; in all other species examined, the nodes 
on proximal part of pennula very much swollen and expanded, 
and very conspicuous, terminal portion of barb smoothly fila- 
mentous, or with very minute prongs. 
11. Order CUCULIFORMES 
This order, composed of two suborders, the Cuculi, including 
the cuckoos and plaintain-eaters, and the Psittaci, including the 
parrots, forms a sort of connecting link between the ground birds 
on the one hand, and the coraciiform and passerine birds on the 
other. Though the cuckoos and parrots are undoubtedly related, 
their being grouped together in a separate order has been open to 
considerable question. In the Cuculi the plumules are very sparse, 
and restricted to the apteria, and the aftershaft is absent or rudi- 
mentary in the Cuculidae, present in the Musophagidae; in the 
Psittaci the plumules are well developed over the whole body, and 
the aftershaft is large, but with a short shaft and no distinct vanes. 
a) Coccyzus americanus 
(1) Remezx 
Calamus very small, and of smaller caliber than shaft. Shaft 
at least as wide as deep at superior umbilicus, the widest part of 
