162 ME. W. P. PYCRAFT ON THE MOEPHOLOGT AND 



The Uropygium is a large, compressed, naked, conical gland lying at the bottom of a 

 conspicuous depression — formed by the great development of the gluteal muscles, — 

 and immediately above the cloacal aperture. A figure of the uropygium will be found 

 in Mr. Beddard's recent paper [8]. 



Rhamphotheca. — Apparently made up of the same elements as in the other Palceo- 

 gnathce ; but this is masked by the greatly elongated form of the beak. There is a 

 distinct cere at its base, but this is not pierced, as in Rhea, Bromceus, and Struthio, by 

 the nostrils. These, in Casuarius, open near the top of the beak, and in Apteryx at 

 its extreme tip, where they will be found as a pair of minute slit-like apertures. 



Podotheca (fig. 2 e). — The acrotarsium may be either made up of large rounded 

 scales, or of large scutes as in Bhea americana. The latter form occurs, so far as I 

 have been able to make out, only in A. australis mantelli. The planta in this species 

 is covered with large coarse papilla?. In an embryo of A. australis mantelli the fusion 

 of small plates into scutes in the acrotarsium is well shown (fig. 7). 



Crypturi. 



The pterylography of this group of the Palceognathce has been described in con- 

 siderable detail by myself [8 1]. It will suffice here to say that the apteria are more 

 marked than in the flightless forms. In the form of the apt. spinale, Calodromas 

 elegans, one of the Crypturi, closely resembles Rhea. Unlike the flightless members of 

 the group, filo-plumes occur — though very sparingly; and down-feathers. These last, 

 however, are restricted to the pteryla alaris. 



The neossoptiles, in the large size of the aftershaft, differ from those of the flightless 

 forms ; but in the remarkable development of the radii and in the elongated flattened 

 shape of the rami, the Crypturi closely resemble the Struthiones (PI. XLV. fig. 2). 



The denticulated tomium of the nestling Calodromas recalls that of Dromwus. 



The Structure of the Feathers. 



The Neossoptiles. 



The neossoptiles of the Palwognatlm consist of prepennse only, but these present 

 many features of great interest. 



The prepennae of Casuarius have a moderately long rhachis, bearing some 3-4 pairs 

 of rami. The radii are unsegmented, of relatively medium length, and bear minute 

 fila, sparsely distributed (PL XLV. fig. 5). The aftershaft is apparently represented 

 by about 6 rami standing at the base of the main shaft, and not seated along a separate 

 rhachis, as in the Fowl or Tinamou. 



The prepennae of Dromceus (PL XLV. figs. 4, 4 a) appear to be distinguishable from 

 those of Casuarius chiefly, and probably only, on account of their rather greater leugth ; 



