OF THE TONGUE OF PARROTS. 249 



In Loriculus (PI. XXIX. fig. 51), Pionopsittacus, Coracopsis, Cyanolyseus, Ecleetus, 

 JVestor, Cacatua roseicapilla, Bolhorhynchus, and Pmoce-phalus robustus the anterior 

 portion of the muscle has undergone still greater retrogression, and is only i-epresented 

 by a muscular band occupying the anterior fifth or slightly more of the inter-ramal 

 space; from the posterior border of the muscle (PI. XXIX, fig. 51,/".) a connective- 

 tissue sheath continuous with its fascia extends backwards to about the posterior end 

 of the rami. 



In Psittacus (PL XXVI. fig. 3), Pyrrliura, Psittinus, and Cacatua (PI. XXVI. 

 fig. 4) the muscle is similar to that just described, but the persistent fascia (/'.) is not 

 so large, and consists of a tract extending from the muscle for a short distance only, 

 with a lateral strip running back along the outer border of the stylohyoideus. In 

 Psittacula and Caica the lateral strips are absent. In Cacatua there is a similar 

 persistent portion of the fascia (/.p.) to the posterior part of the muscle, which extends 

 backwards ; and in C. leadbeateri there is in addition an anteriorly extended fascia 

 devoid of muscle-fibre. 



In Chrysotis, Tanygnathus, Ptistes, Vini, and Lorius (text-fig. 12, p. 251) the anterior 

 portion of the muscle is restricted to the anterior fifth or less of the inter-ramal space, 

 and the persistent fascia is reduced to a pair of lateral strips, which in Chrysotis 

 ochrocephala are very small. In the remaining Parrots the muscle is restricted to the 

 anterior third or less of the inter-ramal area, and there is no representative of the 

 persistent fascia. 



In Cacatua (PI. XXVI. fig. 4), Calopsittacus novce-JioUancUce, Cyanolyseus, Chrysotis, 

 Conurus (text-fig. 10), Psittacus (PI. XXVI. fig. 3), Pceoceplialus, Pytrhum, Coracopsis, 

 Vini, Lorius, and Eos the posterior portion of the muscle is as strongly, or nearly as 

 strongly, developed as the anterior. In Prioniturus, Psepihotus, Platycercus, CaJypto- 

 rhynchus, Cyanorliamphus, Ptistes, Psittacula, Psittinus, Ecleetus, Tanygnathus, Pezo- 

 porus, Pyrrhulopsis, Nasiterna, Loriculus, Bolhorhynchus, Pionopsittacus, Pakeornis 

 (text-fig. 11), and Brotogerys (text-fig. 13, p. 252) the posterior portion is smaller than 

 the anterior ; in the last two Parrots it is very small, and in Brotogerys and Caica has 

 almost undergone complete retrogression, being represented by a few fibres only. In 

 Microglossus and Xestor the posterior portion is absent, the probable meaning of which 

 is that it has disappeared. 



In Microglossus, Cyanolyseus, Ara (text-fig. 15, p. 260), Caica, Pceocephalus, and 

 Pyrrhura both the anterior and posterior portions of the muscle are hidden by the 

 lower bill ; in Eos, Conurus, Psittacula, Tanygnathus, and Nasiterna the anterior 

 portion alone is completely hidden ; in Pff7«orafs (text-fig. 11), Ptistes, Platycercus, 

 Pezoporus, Prioniturus, Psephotus, and Cyanorhamphus the anterior half only of the 

 anterior portion is thus hidden ; and in Cacatua (PI. XXVI. fig. 4) the anterior third 

 only. Ill Brotogerys, Loriculus, Pionopsittacus, Psittacus (PI. XXVI. fig. o). 



