Appendix. 7 1 



less abruptly distinguishable as being composed of two parts. Neither Lifawjus, nor HeUro-pdma, 

 nor Iladrostomus are far from the Mesoniyodian types already known, as far as their voice-organs 

 are concerned, which structural agreement clearly shows that our nomenclature is an inefficient one 

 when it places Hadrostomus as far from Paehyrhainphus as either is from Tityra. 



Again, also, that the Pipridae and Cotingidae should be considered to be different families 

 is not borne out by the nature of the lower larynx ; and it seems hardly possible to allow a 

 difference in tarsal scutellation to constitute a family difference, when not borne out by more 

 important points of internal structure. 



Menura snfwha is another bird in which our knowledge of the structure of the syrinx is 

 very deficient. Mr. Eyton has described it'; but his account will bear supplementing. He tells 

 us that ' in addition to the usual sterno-tracheal muscles this curious bird has two other pair, 

 both of which have their origin on the rings of the trachea on each side, at the point where 

 it enters the cavity of the thorax. The anterior pair is inserted on the knobs at the extremities 

 of the fourth bones of the bronchiae ; the posterior pair are also inserted on the bronchiai', but 

 on the three uppermost rings and on the posterior extremity of the fifth.' 



In Menura superba the last sixteen rings of the trachea are fieculiarly narrow from above 

 downwards. These are carinate in front; in other words, instead of being flattened from without 

 inwards (as is usually the case, and is so in the rings above the sixteenth in this bird), they 

 are compressed from above downwards, by which means a sharp-edged ridge is developed, which 

 projects outwards a short way beyond the level of the interannular membrane. The lowest of 

 these rings, the last tracheal, whilst participating in this peculiarity, is modified to form the 

 three-way piece, whence start the bronchi, an antero-posterior bar joining the downward-directed 

 angles which are developed on the middle of the front and back of the ring, and supporting the 

 syringeal semilunar membrane. 



As in the typical Oscines, the first three bronchial semi-rings participate in the formation 

 of the syrinx, and are modified accordingly, being stronger, deeper, more flattened, and more 

 approximate than tJiose which follow. The first of these is simple ; the second is peculiar in 

 being hollow aud thin-walled, broader in front than behind, and broadest a short distance 

 (about equal to its depth at the spot) posterior to its anterior extremity ; the third is narrower, 

 and terminates behind by a short descending hook. 



The syringeal muscles are three in number on each side at their insertion, although at their 

 origin only two can be distinguished. These are an anterior and posterior longitudinal, which, 

 from a lateral poi)it situated opposite the tracheal ring 19 above the last one, diverge foi^wards 

 and backwards to the tips of the bronchial semi-rings. In Plate VII, figs, i, 2, and 3, the 

 front, back, and side views of the syrinx of Menura are figured. 



The anterior longitudinal muscle, whose diameter is about four times that of the depressor 

 tracheae, is of uniform size throughout, being constituted of parallel fibres. It is inserted into 

 the lower margin of the expansion at the anterior extremity of the second bronchial semi-rin", 

 at a short distance behind its apex. 



The posterior longitudinal muscle, from being single above, divides into two below. 



' Ann. & Mag. Nat. Hist. 1841, vol. vii, p. 49. 



