PHYLOGENY OP THE PAL-EOGNAT1LE AND NEOGNATH-E. 269 



process of quadrate long, articulating with whole inner border with 



pterygoid ; olfactory cavity of great size Dinornithidce. 



c. Vomer deficient posteriorly, not extending backwards to reach the pterygoid, 

 anteriorly extending forwards, as in Dromaus, to conceal the parasphe- 

 noidal rostrum ; the body of vomer deeply hollowed, fitting closely on to 

 the rostrum, and embraced on either side by the maxillo-palatine pro- 

 cesses ; maxillo-palatine processes hastate ; anterior palatine processes of 

 great size ; pterygoid laminate ; palatine rod-shaped, fused proximally 

 with external border of pterygoid ; premaxilla wanting a palatine process ; 

 lachrymals continued backwards to fuse with a chain of supra-orbitals 

 and with the fiontals, so as to enclose a supra-orbital foramen ; lachrymal 

 with an osiculum lachrymo-palatinum; nostrils holorhiual ; anterior narial 

 and lachry mo-nasal fossae confluent ; quadrate with long recurved 

 process bearing a well-defined projecting facet for the pterygoid in 



the middle of its internal ventral border Strut Mo. 



B. Beak elongated, decurved, probe-shaped ; anterior narial fossa minute, con- 

 fined to tip of beak; lachrymo-nasal fossa enormous, extending forwards to 

 within a short distance of tip of beak ; skull rounded, without post-orbital 

 processes; lachrymal vestigial; olfactory chamber of great size, extending 

 backwards to optic foramen ; vomer passing backwards to fuse with the 

 pterygoid and palatine, and, with these, helping to form the floor of a 

 tubular recess opening inwards Apteryx. 



Key to the Species. 

 Struthio. 



a. Maxillo-palatine processes not rising dorsad, the anterior border of the 



maxillo-palatine process at right angles to the long axis of the "skull. 

 a'. Palatines projecting distad beyond anterior border of maxillo-palatine 

 process ; maxillo-palatine processes without any external lateral fenes- 

 trated plate S. australis. 



b'. Palatines not reaching as far forward as the level of the anterior border of 

 the maxillo-palatine process. 

 a". Vomer very short ; parasphenoidal rostrum thick ; maxillo-palatine 



processes with an external lateral fenestrated plate S.molybdophanes. 



b" . Vomer very long ; maxillo-palatine processes without an external lateral 

 fenestrated plate ; parasphenoidal rostrum slender ; roof of the skull 

 with deep depressions mesiad of the supra-orbital ledges ; nasals 

 meeting in the middle line proximad of the nasal process of pre- 

 maxilla S. iiwridioita/is'. 



b. Maxillo-palatine processes rising dorsad ; anterior border of maxillo-palatine 



processes sloping obliquely backwards ; vomer broad, with short, pointed, 

 posterior limbs ; palatines projecting distad beyond maxillo-palatine pro- 

 cesses S. camelus. 



1 We believe that Struthio massaicus (Neum.) is identical with this bird.— W. It. & W. P. P. 



vol. xv. — part v. No. 21. — JJecember, 1900. 2 p 



