224 ME. G. p. MUDGE OX THE MYOLOGY 



seijaratiou, and the secondary attachment of the muscle to the tendon, is actually seen 

 in Cacatua leadbeaieri. Why the assumption of this particular condition should be 

 confined to the left side, or why the asymmetrical departure should always occur on 

 the left side, is a question which the present range of facts cannot answer. 



In Nestor notahilis (PI. XXIX. fig. 46) the ceratoglossus inferior posticus {cg.i.p.) 

 only extends back along the anterior two-thirds of the hypobranchial, and its tendon 

 is very strongly developed. A ceratoglossus inferior anticus accessorius is absent. 



Stage 7. 



In this stage the ventral fascia nf the ceratoglossus inferior anticus is no longer 

 tendinous, as a consequence of which the tendons of the ceratoglossus inferior posticus 

 and ceratoglossus lateralis are independent, except at their common origin at the 

 anterior lateral process. The tendon of the ceratoglossus inferior posticus is slightly 

 more strongly developed than in the earlier stage, and without a single exception the 

 muscle itself extends back to the posterior limit of the hypobranchial (=f). The 

 inner portion of the ceratoglossus inferior anticus has completely disappeared (=111) 

 in about one-half of the muscles examined. 



In I'yrrhu7'a leiccotis (PI. XXIX. fig. 40) the muscle exhibits the highest characters 

 of this stage, ?'. e., the tendon is well developed and spreads out to a small degree in a 

 fan-shaped form at its attachment to the ceratoglossus inferior posticus ; the latter 

 extends along the whole length of the hypobranchial, and the inner portion of the cerato- 

 glossus inferior anticus has disappeared. In Nymjjhicus uvceensis and Cyanorhamjms 

 aurice])S the muscle is similar to that in Fyrrhura. In Loriculus galgulus (PI. XXIX. 

 fig. 42) the inner portion of the ceratoglossus inferior anticus persists as a small 

 vestige (= between II & III) and smaller posteriorly than anteriorly. The tendon 

 spreads out in a fan-shaped form upon the ventral surface of the ceratoglossus inferior 

 posticus at its junction with that, and upon the dorsal surface it runs back as a narrow 

 tract, similar to that on the ventral surface of the muscle in Lorius f.avo-])alliatus 

 (PI. XXIX. fig. 38). In Psittacula ■passerina the muscle (PL XXIX. fig. 41) is 

 similar to that in Pyrrhura, except that the inner portion of the ceratoglossus inferior 

 anticus is like that in Loriculus. The ceratoglossus inferior anticus accessorius {cg.i^.) 

 is supplemented by a second one (cg.i^.), which arises not from the parent muscle itself, 

 but from its tendon. I propose to call it the ceratoglossus inferior anticus acces- 

 sorius secundus. In Caica leucogaster the muscle is similar to that in Pyrrhura, though 

 the tendon is somewhat thinner, and the inner portion of the ceratoglossus inferior 

 anticus persists, and for this stage is strongly developed ( = 11). 



In Py.rhulojjsis spletidens the muscle exhibits several peculiarities : the inner 

 portion of the ceratoglossus inferior anticus is almost primitive on the left side, since 

 it reaches to the middle line as in Ara macao (PL XXVIII. fig. 27) ( =. I), but on 

 the right side it has retrogressed to stage II ; and anteriorly, that of the latter side 



