1900.) SHUFELDT—OSTEOLOGY OF THE STRIGES. 6383 
As in almost all Owls, the mastoidal part of the quadrate is nota- 
bly long; and the well-developed basipterygoidal processes are 
present for articulation with the pterygoids. Palatines are not 
very wide, and they are inclined to be bowed outward along their 
lengths. Maxillo-palatines, too, are comparatively small and well 
separated from each other in the median line. They are of the 
same spongy structure that we see in the S¢riges generally. I am 
inclined to think that the vomer never ossifies in Sfeoty/o, and, as 
we know, it is very small in a number of other Owls. 
This little Burrowing Owl possesses a mandible of a form com- 
mon to most of its family. A large ramal vacuity is always present 
in it upon either side, and the bone is pneumatic. 
Speotyto has its orbits of comparatively large size, and the 
_ sclerotal plates of the eye itself are strong and ample. 
The hyoid arches are suspended from the base of the skull by 
‘their usual attachments. In this Owl they consist of six separate 
little bones, involving five articulations. The tips of the upturned 
posterior extremities are about opposite the lower borders of the 
temporal fosse, its two limbs diverging from each other at an 
angle equal to that made by the lower mandible. The ceratohyals 
are rather large in comparison with other bones. They are joined 
both anteriorly and posteriorly by bony bridges, forming a fenestra 
between them to be filled in by a thin membrane. The amount of 
divergence they make from each other is less than that made by 
the epibranchial elements of the thyrohyals. Anteriorly the bone 
connecting them supports a cartilaginous glossohyal, while the pos- 
terior connection presents for examination the usual smooth articu- 
lating surface that enters into the arthrodial joint it makes with the 
basibranchial. The first basibranchial and second _ basibranchial 
are confluent, not a sign of the point of union remaining. The 
latter bone is continued a short distance posteriorly by a tip of 
cartilage. The anterior end of the first basibranchial is devoted to 
the articular surface for the bone connecting the ceratohyals, form- 
ing the joint mentioned above. It is concave from above down- 
ward, convex from side to side, the lower lip being the longer. It 
will be plainly seen that this combination grants to the tongue a 
movement in the vertical and horizontal planes. The anterior 
articulating heads of the epibranchial elements of the thyrohyals 
are opposite each other, each being received into the diminutive 
acetabulum intended for it at the side of the united first and second 
PROC. AMER. PHILOS. soc. XXxIXx. 164. Ss. PRINTED JAN. 19, 1901. 
