INTEODUCTIOX. 



xxxiu 



Fig. 16. 



(From P. Z. S. 1895, p. 164, fig. 1.) 



B 



ch &?> -P 



Hycid of Psittacus eritliacus. 

 A. Dorsal aspect ; B. Ventral aspect : C. Lateral aspect. 



b. Basihyal. 



c. Concavity or cup-like elevation. 

 ch. Ceratobranchial. 



e. Entoglossum. 



lib. Hypobranchial. 

 p. Parahyal process. 

 u. Urohyal. 



This arch hears a singular resemblance to an os furculum, its symphysis (figs. 17 & 19, h, 

 & fig. 18, s) calling to mind the " hypocleidium." 



It would seem to be probable, then, tbat the Loriidee may be distinguished from the 

 other Psittaci by the possession of a parahyal arch. 



It would be rash to assume that no such arch exists in any one of the other families, 

 subfamilies, and genera of Psittaci ; nevertheless, as hardly any of them possess a brush- 

 tongue, we may well suspect a parahyal arch to be peculiar, or almost peculiar, to the 

 Loriidee. Only in the Nestor and in Nanodes is any structure at all comparable to the 

 tongue of the Lories known to exist. It becomes therefore a matter of much interest 

 to find out what is the hyoidean structure of those two genera : this we have been enabled 

 to ascertain. 



e 



