STUDIES OE THE MACEOCHIEES. 
331 
blade-like portion behind is very thin, its surrounding margin 
only being thickened to lend it the proper support. 
When we come to measure the lengths of the bones composing 
the pectoral limb in this Trogon, we find that the humerus is 
3'1 centimetres long, the ulna 36 ; and the skeleton of manus, 
measuring from the summit of the carpo-metacarpus to the distal 
apex of the last phalanx of index digit, 3'0 centimetres long. 
Of the Felvic Limb (PI. XIX. fig. 13). — Trogons have a 
thoroughly pneumatic femur, and a large foramen or two to 
admit the air are found upon the anterior aspect, near the sum- 
mit of the bone, between the trochanter and the head. I am not 
quite certain but that the tibia also possesses a moderate amount 
of pneumaticity, as the shaft is completely hollow and the bone 
has the general appearance of a pneumatic one. However, I 
have failed to discover the presence of the foramina in this part 
of the skeleton of the leg. As for the fibula and the remaining 
skeletal parts of this limb, they are entirely devoid of this 
feature. 
Returning to our examination of the femur, it is to be noted 
that the trochanter is but feebly pronounced, and does not rise 
above the summit of the bone. The caput femoris is globular 
and quite sessile with the shaft. We can scarcely discern any 
pit whatever upon its superior surface to lodge the attachment 
of the ligamentum teres. Descendiug to the shaft we find this 
part of the bone nearly cylindrical in form, very smooth, and 
quite straight. At its distal extremity the condyles are rather 
small comparatively ; the external one being situated lower, and 
at the same time somewhat more prominent than the internal 
one. 
Trogons possess a very well-developed patella of a subcordate 
form, it being fully twice as wide as it is deep. 
Regarding the fibula, we find that it presents little or nothing 
worthy of special note. Feebleness of development charac- 
terizes this bone in the Trogons throughout. Jts head is 
small and the shaft slender, the lower end of the latter being 
free from the tibia, and descending to a point about opposite the 
junction of the middle and lower thirds of its shaft. Scarcely 
any evidence exists of the presence of the tubercle for the inser- 
tion of the tendon of the biceps muscle, a feature which is 
quite prominent in some birds. 
LINN. JOUEN. ZOOLOGY, YOL. XX. 
26 
