20 On the Pterylography of the Tinaniiformes. 



to tlie pterylography of the Tinaniiformes; the remaining 

 papers represent the literature of pterylography in general. 



EXPLANATION OF THE PLATES. 



Plate I. 



Left side view of Calodromas etegans, showing the distribution of the 

 pterylae (feather-tracts). The shaded parts represent the apteria. 

 Large dots indicate the presence of thick-shafted feathers (p. 8). 



Apt.a.mf. Apterium alae inferioris. 



Apt.c.lat. „ colli lateralis. 



Apt.t.lat. „ trunci lateralis. 



Apt.m. ,, mesogastrfei. 



Apt.sp. „ spinalis. 



Ft.caj). Pteryla capitis. 



Ft. col. kit. „ colli lateralis. 



Pt.cr. „ cruralis. 



Ft.f. „ femoralis. 



Pt.S2}. „ spinalis. 



Ft.v. „ ventralis. 



Hp. Ilypopteron. 



[■''. Uropygium (oil-gland). 



Plate II. 



Dorsal aspect of Calodromas elegans, showing the arrangement of the 

 feather-tracts (pterylse). The shaded parts represent the apteria. 



Additional Letters. 

 Pt.e. Pteryla caudalis. 



Pt.h. „ humeralis. 



Par. Parapteron. 



Plate III. 



Fig. 1. A "nestling-down " feather (neossoptile) from the spinal tract of 

 a recently-hatched example of Calodromas elegans ; magnified 

 and slightly diagrammatic, showing the highly developed radii 

 at the distal end of the feather and the large aftershaft (Hypo- 

 rhachis), H. 



Fig. 2. Three radii from the distal end of the feather shown in fig. 1 

 highly magnified. These radii are apparently composed of a 

 number of segments, such as is shown in fig. 3, which have 

 become fused. The " cilia," it will be noticed, occur only on 

 the penultimate and two preceding segments as a prolongation 

 of the ventral angle of the laminated segment. 



