162 MR. W. P. PYCRAFT ON THE MORPHOLOGY 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 Palwo- 
gnathe ; 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, Dromeus, and Struthio, by 
the nostrils. These, in Caswarius, 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 £).—The acrotarsium may be either made up of large rounded 
scales, or of large scutes as in Rhea 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 papille. 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 Palwognathe has been described in con- 
siderable detail by myself [81]. 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 (Pl. XLV. fig. 2). 
The denticulated tomium of the nestling Calodromas recalls that of Dromeus. 
THe STRUCTURE OF THE FEATHERS. 
The Neossoptiles. 
The neossoptiles of the Palewognathe consist of prepenne only, but these present 
many features of great interest. 
The prepenne of Caswarius 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 prepenne of Dromeus (Pl. XLV. figs. 4, 4a) appear to be distinguishable from 
those of Casuarius chiefly, and probably only, on account of their rather greater length ; 
