316 DR. ST. GEOBtrE JIIVAET ON THE SKELETON Of [-A-pr. 2, 



spine (n) is quadrate and directed almost exclusively dorsad, instead 

 of being obtusely pointed and directed postaxiad as in P. erithams. 

 The postzygapophyses are almost entirely devoid of hyperapo- 

 physes. There are small and flattened ones as in P. erithacus. 

 The postaxial margin of the pleurapophysial lamella also shows 

 two superimposed postaxiad processes, the more ventral of which is 

 continuous with the ridge bounding externally the antero-posterior 

 groove on the ventral surface of the parapophysial lamella. The 

 prezygapophysis bears a small prominence on its outer surface, 

 which becomes noteworthy in the next vertebra. 



Fig. 6. 



Lateral aspect of 3rd to 12th vertebrae of Psittacm erithacus. 



c. Catapophysis. 



d. Diapophysis. 

 /. Foramen. 



h. Hypapophysis. 

 hp. Hyperapophysis. 

 m. Metapophysis. 



n. Neural spine. 

 pi. Pleurapophysial lamella. 

 ptz. Postzygapophysis. 

 pz. Prezygapophysis. 

 st. Styliform process. 



The fifth vertebra has the postzygapophyses much lengthened 

 in both species, but especially in L. fiavopalliatus, in which also 

 the neural spine is smaller and more quadrate in outline. It 

 arises some distance behind the preaxial end of the neural arch. 

 In both species the hyperapophyses (hp) have the form of two 

 small ridges diverging postaxiad from the hinder end of the base 

 of the neural spine — more marked in L. fiavopalliatus, in which 

 species the hypapophysis is small and extends preaxiad from just 

 behind and below the anterior central articular surface. 



The ventral margin of the vertebra is much more antero-posteriorly 

 concave than in P. erithacus. The ventral antero-posterior groove 

 on the parapophysial lamella is almost obsolete, but the, here ex- 

 panded, outer surface of the pleurapophysial lamella shows, above 

 and preaxially, a rough prominent process {metapophysis) on the 

 outer surface of the prezygapophysis (there is a rudiment of the 

 metapophysis in the fourth vertebra), and, more ventrally, a very 

 small process near the antero-inferior angle of the lamella on 

 either side. These are caiapophyses ' (c). The ventral margin of 

 that lamella gives rise at its postaxial end to a short styliform 

 pleurapophysial process (st), which seems to answer to the lower 

 of the two superimposed processes of the third vertebra. The 

 higher of the two is much extended and joins the under surface of 



^ See op. cit. p. 401, 



