240 Mr. W. P. Pycraft on the 
ITV. Ostro.oey. 
Ostcologieally, the Colies present many peculiarities which, 
so far as the adult skeleton is concerned, make this group 
appear more isolated than is really the case; and this is 
especially true of the skull. 
The Skull of the Adult. 
The Skull (text-fig. 17).—The most conspicuous feature of 
the skull, in the adult, is the spherical shape of the cranium, 
the feeble development of .the postorbital process (which may 
be described as obsolete), the vestigial lachrymal, and the 
Text-fig. 17. 
Lateral aspect of the skull of Colius capensis. x2. 
a.o.p.=antorbital plate. pt.=pterygoid. 
p.0.p.=postorbital process. y.=quadrate. 
pa. =palatine. 
palate (which is indirectly desmognathous) ; while the inter- 
orbital septum is complete and the nares are divided by a 
bony septum. 
The tympanic cavity is relatively small, oval, and rather 
shallow. The lateral wing of the exoccipital, which forms 
the posterior boundary of this cavity, rises upwards to pass 
insensibly into the processus articularis sqguamosi, but there 
is no squamosal prominence. ‘The recessus tympanicus 
anterior, which opens into this cavity, is small; while the 
