286 MR. W. K. PARKER ON THE OSTEOLOGY OF BAL/ENICEPS REX. 
cellaride, e.g. the Short-tailed Petrel (Puffinus brevicauda), from Green Island, Bass’s 
Straits (1224, Osteol. Cat. Mus. Coll. Chir. vol. i. p. 230). 
Group 5.—Fronto-maxillary hinge more or less moveable and splint-like ; palato- 
pterygoid joints freely gliding on a more or less synovial ‘rostrum’; ento-pterapophysis 
longer and more delicate, as is its answering apophysis on the pterygoid ; the facets 
of this little apophysis are rather round than oval, and their position more backward, 
being midway between the palatine and os quadratum: in this group the vomer is 
often well developed and cellular. 
Examples :— 
Strix, Ulula, Asio, Bubo (Owls). Charadrius hiaticula (Ring Dotterel). 
Columba, Palumbus, Treron  chlorogaster, Scolopax (Snipes and Woodcocks). 
Goura victoria, Geophaps smithii (the typi- Limosa melanura (Godwit). 
cal Pigeons). Numenius arquata (Curlew). 
Vanellus cristatus (Lapwing). Tringa variabilis (Sandpiper). 
Group 6.—No movement of the facial on the cranial sclerotomes, the differentiation of 
the ethmoid and pre-sphenoid in the cranio-facial axis being soon obliterated by the 
fusion from below upwards of these vertical centrums. The rostrum is large, and the 
ento-pterapophyses unusually well developed; but they are not connected with the 
anterior part of their own hzmal bones, the pterygoids, as in Fowls and Geese, nor with 
the middle, as in Owls, Pigeons, and Snipes, but articulate with a facet on the distal 
end of these bones, which are wedged in between the ento-pterapophyses and the 
quadrate bones. 
In these non-typical birds the pre-maxillaries are relatively small and feeble (as the 
rule), the maxillaries unusually large, and lying in the same plane as the pre- 
maxillaries ; the palatals small, and pushed aside (so as to resemble the ‘ transverse 
bones’ or ‘ecto-pterygoids’ of the Crocodile) by the unusual development of the 
vomer, which, thin, broad, and split at both ends, passes backwards to articulate with 
the pterygoids. These latter bones are not at all bird-like, but have taken on much of 
the laminar character of their homologues in the Reptilia, and are adapted to the 
vomer by a squamous suture, whereas in typical birds they articulate with the palatines 
by a synovial joint. 
Example :—Struthionide (the Ostrich family). 
Orbito-sphenoid. (Pl. LXV. fig. 1, os.) 
Looking at the middle part of the well-formed orbital roof of Baleniceps towards 
the axis, we see a small foramen two lines above the oval membranous space already 
mentioned as a landmark between the ali- and orbito-sphenoids. This small foramen 
pierces the sphenoido-frontal just above its union with the diverging plate of the orbito- 
sphenoid. Five lines in front of and a little above this passage is another, scarcely 
