STEREORNITHES 907 
In a smaller species, P. inflatus, of which more remains than of any 
other have been recovered, the entire head measures 340 mm., or 
nearly 13°5 in. The tarso-metatarsus of what Dr. Ameghino considers 
to be a species of intermediate size, P. sehuensis, is about 14°25 in. 
long and 3 in. wide; and he figures an example of the tibio-tarsus 
of P. inflatus which he says is 400 mm., or say 15°75 in. in length. 
The femur measures 230 
mm., or about 9 in. 
In brontornis the 
mandibular symphysis is 
shorter, wider and more 
sharply curved upward 
at the tip, while the 
rami are more divergent, 
their approximate length 
being 5°5 in., and maxi- 
mum width 4 inches. 
The tarso-metatarse in 
this genus is relatively 
shorter and stouter than 
in Phororhacos, having a 
length of about 15:5 in., 
and a maximum distal 
width of 5-25 in. The 
associated tibio-tarsus of 
Brontornis, measures 30°5 
in. and the former 15°5 
in. The species, JB. 
burmeisteri, therefore at- 
tained a stature approxi- 
mately equal to that 
assigned to A’pyornis 
maximus. 
On the remaining PHORORHACOS INFLATUS, 
members of this Family a, coracoid ; 6, proximal end of scapula; ¢, distal end of 
: P huinerus; d, ulna; e, metacarpus. (After F. Ameghino.) 
and of  Opisthodactylus 
there is no need now to dwell, for the remains discovered are 
insufficient to admit of their being considered to any useful purpose. 
With regard to the general affinities of the Stereornithes it is 
impossible to say much at present ; but more than one writer has 
remarked on the resemblance in several points offered to Gastornis 
of the European Lower Eocene, the tibio-tarsus of the latter having a 
distal bridge and a deep intercondylar furrow, while its tarso-meta- 
tarsus has a prominent intercotylar tuberosity, and the relative length 
of the distal trochlee is similar. It is true that the distal end of the 
tibio-tarsus is inflected in the European genus; but the example of 
