218 MR. G. r. MUDGE ON THE MYOLOGY 



the cxccpfioiKil condition of the latter is foreshadowed in tliat of the former, and that 

 it could liinc arisen, and doubtless has arisen, by the completion of tlie incipient 

 retrogression which is indicated in the region {r., text-fig. 2), and by tlie development 

 of the tendinous prolongation (t.) into a distinct tendon. 



The muscle in Cacatua suljj/ivrea is lil<e that in Cacatua leadbeateri, but the cerato- 

 glossus inferior posticus only extends along one-third of the length of the hypobranchial, 

 in respect of which it resembles that in Stringops. 



In Caloxisittacus novce-hoUcmdlce (text-fig. 3) the muscle is like that in StringojJS, 

 luit the inner portion of the ceratoglossus inferior anticus is not so strongly developed. 



In Kasiterna pusio the muscle is similar to that in Stringops, but the tendinous 

 portion of the ventral fascia (PI. XXIX. fig. 48) is restricted to a conical tract extending 



C!?.i.a. 



cg.ip. 



Calopsittacus noiw-hollandice. — Dorsal view of ceratoglossus inferior (left side). A similar preparation to that 

 of fig. 1. (Twice nat. size.) Lettering as in text-fig. 1. 



from the insertion at the anterior lateral process, over the ventral surface of the 

 anterior portion of the muscle, to its attachment to the ceratoglossus inferior posticus 

 (posterior portion of the muscle) {cg.i.p.). The attachment of the latter portion of the 

 muscle to this tendinous tract is somewhat more anteriorly situated than in Stringops 

 or any other Parrot. The outer portion {cg.i.a.) of the ceratoglossus inferior anticus 

 is more strongly developed in its lateral extension than in most instances, while the 

 inner portion [cg.i.a^.) does not extend back on to the urohyal. 



The third stage is thus characterized by the fact that the posterior extension of the 

 ceratoglossus inferior anticus of Stage 2 has separated from the parent muscle, but 

 remains connected with that by attachment to a small prolongation of its ventral 

 tendinous fascia, by the greater extension of the ceratoglossus inferior posticus along 

 the hypobranchial, and by a slight retrogression of the urohyal origin of cg.i.a^. 



Stage 4. 

 This stage is characterized by a slight retrogression of the inner border and posterior 

 extremity of the inner portion {cg.i.a^.) of the ceratoglossus inferior anticus, and by the 

 development in an antero-posterior direction, in the ventral tendinous fascia, of a very 



