1889.] MR. W. K. PARKER ON STEATORNIS CARIPENSIS. 181 
(Caprimulgus and Chordeiles), there is a rudiment in Steatornis, in 
Cuculus canorus, and in Buceros ruficollis; this part is nearly as 
large in Geococcyx affinis as in Apteryx. 
In Ceryle alcyon the post-ilium sends backwards a process (its 
proper termination) over the ischium, which only measures 1°5 
millim.; this spur is very long in Steatornis; it is 10 millim. in 
length; the ischium and pubis both project far backwards also as 
long ligulate processes, cartilaginous for their greater part. The 
pre-ilium (pr.z.) in Steatornis sends forwards a spike in front of the 
ear-shaped fore lobe of the bone; this is formed by the junction of 
the inner edge of the bone with the diapophysis of the underlying 
vertebra—the 1st sacral. 
The “sacro-ischiadic ” fenestra (s.i.f.) is oval; it is 8 millim. 
long by 4 millim. wide; its broad end is in front. The bony junc- 
tion of the post-ilium (pé¢.i.) and ischium, behind this fenestra, is 
1°5 millim. in extent. 
The ischium (ise.) runs back quite free from the pubis (pb.) ; it 
keeps at a distance from it; its whole length is 38 millim., and its 
free projection, next below that of the post-ilium, is 13 millim. long ; 
it is 6 millim. wide in front of the fore part. 
The pudis is only 2 millim. wide in front and 3 millim. behind; 
its whole length is 47 millim., and the chord of the are formed by 
this rib-like bone behind and the pre-ilium in front is 74 millim. 
This is a peculiar form of pelvis, so broad, gently convex, and free 
from all strong outgrowths; it is only in birds whose hind limbs are 
small and feeble, such as Cypselidz, Trochilide, Alcedinide, and the 
like, that such a pelvis is possible. Even among the Cuculines, 
whenever the legs are strong, we get a great contrast to this, e.g. 
the Musiphagide, and such Cuculide as Sawrothera and Geococcyz. 
The Hind Limbs (Plate XIX. figs. 4, 5) of Steatornis are, as I 
have said, only half as large as the wings; I here compare them, in 
the measurement of the main regions, with those of the Kingfisher 
aud Goatsucker :— 
Tarso- 3rd 
Herm: ee metatarsus. digit. 
millim. millim, millim. millim. 
Ceryle aleyon ...... 29 39 12°5 24 
Caprimulgus europeus 21°5 29 14 20 
Steatornis caripensis.. 38 48 id 37 
Here we see that, roughly speaking, the femur (f.) is three 
fourths the length of the tibia (¢.) in Ceryle and Séeatornis, and a 
little more than two thirds in Cuprimulgus. 
The tarso-metatarsus (¢.mé.) is little more than half the length 
of the 3rd digit in Ceryle, more than two thirds in Caprimulgus, and 
considerably less than half in Steatornis. 
The relative size of the bones of the leg and foot, on the whole, 
in the last of these birds is very similar to what we find in the Cyp- 
selide, Caprimulgidee, and Alcedinide ; for in all these families the 
hind limb is very feebly developed. This is very marked also in 
Proc. Zoot. Soc.—1889, No. XIII. 13 
