1895.] LOEIUS FLAYOPAXLtiTtrS AHD PSITTACUS EEITHACTJS. 32l 



The most striking difEerence is the reduction in size of the pleur- 

 apophysial lamella {pi) antero-posteriorly. It has become a delicate 

 ridge of bone, narrower antero-posteriorly than dorso-ventraily. 

 It is antero-posteriorly grooved externally, the groove being 



Fig. 10. 



..pz 



t^ // 



'■" ptz 



St' 

 c ■ ' 



k - 



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



c. Catapophysis. 



d. Diapophysis. 

 h. Hypapophysis. 



pi. Pleurapophysial lamella. 



Pkoc. Zool. Soc— 1895, No. XXI. 



j}tz. Postzygapophysis. 

 2>z. Prezygapophysis. 

 st. Styliform lamella. 



21 



