1901.] OlSr THE LINGUAL MYOLOGY OF PARROTS. 277 



showed au extensive inflaunnatory tuniour on the right side, con- 

 nected by a pedicle to the inner surface of the skull, perforating 

 the bone by a circular opening, and causing thickeniiDg and breaking 

 up of the horn-support. 



Mr. Holding also exhibited the skull and horns oF another 

 Japanese Deer, showing a curious spur growing from tbe pedicle 

 of the right horn, an uncommon position for a supernumerary 

 horn ; such horns, when they do occur, usually having their ongin 

 below the pedicle or above the burr. 



Mr. G. P. Mudge gave an account of his researches on the 

 Lingual Myology of Parrots, with a Classification of the Order 

 based upon the structure of the Tongue. The ceratoglossus 

 inferior exhibited structural modifications which could be grouped 

 in nine stages, arranged in a graded series. In its most primitive 

 foi*m it consisted only of an anterior portion related to the basi- 

 hyal ; and in its most speciahzed condition of an additional posterior 

 portion related to the hypobranchial, and connected with the 

 anterior part by a strongly developed tendon. The primitive 

 muscle possessed no tendon but a tendinous fascia. All stages in 

 the development from the primitive to the specialized condition 

 could be traced, in the form of a gradual posterior extension of 

 the anterior primitive muscle along the hypobranchial and in the 

 gradual thickening of a localized, elongated tract of the tendinous 

 fascia, with its concurrent posterior extension along the developing 

 posterior portion of the muscle. In Brotogerys and Ptistes the left- 

 and right-hand muscles were not alike, and it was shown that the 

 exceptional left-hand muscle of the latter Parrot could be directly 

 derived from that of Cacatua leadheateri by the completion of the 

 incipient retrogression there indicated. In virtue of the structural 

 features of this muscle, Cacatua, Stringoios, Am, Calopsittacus, and 

 Calyiotorhynclius were primitive, and the Lories w^ere specialized ; 

 but some species of Cacatua and Ara were more advanced than 

 others of the same genera. 



The thyroglossus had arisen from the thyrohyoideus in three 

 ways, each of which evolved along its own line through two stages : 

 at the third stage all three ways converged, whence the further 

 evolution of the muscle could be traced through three higher stages. 

 The insertion and origin of the muscle in the highest stage was 

 similar to that of its most primitive condition ; but it was shown 

 that there w^ere reasons for regarding this apparently primitive 

 condition as resulting from a secondary return to the original one. 



The thyrohyoideus was shown to be much more extensive in 

 its primitive condition than was now represented in the majority 

 of Parrots. In respect of this, Cacatua, Stringops, Calopsittaciis, 

 Calyptorhynclms, Microglossus, Eclectus, and Nestor were primitive, 

 since they possessed in the form of a thyrohyoideus accessorius 

 evidence of the once more extensive nature of the muscle. 



In Stringops the anterior mylohyoideus extended back to the 

 Pboo. Zool. Soc— 1901, Vol. I, No. ZIX. 19 



