PHYLOGENY OF THE PALZOGNATHZ AND NEOGNATH&. 179 
In Dromeus the outer fork of the >-shaped notch of the upper limb is greatly 
developed, forming a long, backwardly directed, spine-like supra-orbital process 
(Pl. XLII. fig. 2). The inferior limb is notched below the lachrymal foramen. 
In D. nove-hollandie the inner fork of this notch is short and confluent with the 
free edge of the ventral border of the antorbital plate. The outer fork is produced 
downwards far beyond this, and rests upon the quadrato-jugal bar. In D. irroratus 
and D. ater the outer and inner forks of the prong are subequal, and do not quite 
reach the level of the ventral border of the antorbital plate, which is continued 
downwards by means of a slender column on to the maxillo-palatal process, where it 
expands. 
In Struthio (Pl. XLII. fig. 3) the outer fork of the upper limb is comparatively 
short and blunt, and projects more laterally than in the above mentioned. Further- 
more, it differs in that it is joined by a series of large bony scales lying between its 
posterior extremity and the supra-orbital ledge of the frontal, recalling the supra- 
orbital chain of bones in the Tinamou. Late in life the scales fuse with the lachrymal 
in front and the frontal behind, thus enclosing a large supra-orbital foramen. The 
lower limb of the lachrymal takes the form of a slender backwardly curved rod, whose 
free end is curved sharply outwards to join the inner border of the quadrato-jugal bar. 
To the inner side of this outwardly directed free end is attached a larger ossiculum 
palatinum, which in the adult fuses with the lachrymal on the one hand, and the 
antorbital plate on the other. Below the ventral border of its*inner end comes in 
contact with the palatine. 
Apyornis and Dinornis have the lachrymal so completely fused with the frontal 
and antorbital as to be with difficulty distinguishable. ‘The upper limb in both has 
completely merged into the supra-orbital ledge. The lower in Dinornithide is much 
flattened antero-posteriorly. The lachrymal foramen is imperfect, its outer bar being 
wanting. In some, e.g. Anomalopterya, it is perfect. Its ventral extremity is squarely 
truncate and articulates with the maxillo-jugal bar. 
In the only 4pyornis skulls I have been enabled to examine, this lower limb has 
been broken away. 
In both these groups the anterior border of the lachrymal rests against a well- 
marked, spine-like, maxillary nasal process. 
In Apteryx the lachrymal is described by Parker [71], from young specimens, as “a 
small irregular bone consisting of a shell-like central portion applied to the surface of 
the aliethmoid, and of an ascending portion which articulates with the descending 
process of the nasal. It is perforated obliquely by the lachrymal foramen.” In the 
adult it is completely fused with the aliethmoid. Its anterior border is often traceable 
as a thin suture between it and the maxillary process of the nasals. 
In the Crypturi the lachrymal is indistinguishably fused with the nasal, and forms 
therewith a prominent outstanding process bounding the orbit in front. There are no 
backwardly projecting spines. The ventral limb fuses with the antorbital plate. 
