1883.] 



APPARATUS OF THE TENUIROSTRES. 



63 



and as they likewise slightly curl up, two secondary tubes, more or 

 less completely closed, are formed. Further in front, these median 

 edges become laciniated in various ways. Towards the tip of the 

 tubes the greater portion of the thin lamella constituting them 

 splits up into bristles ; but the outer edge seems to remain intact. 

 The mode of splitting up, or the shape of these lacinise, vibrissas, or 

 bristles of the median parts of the tubes seems to be characteristic 

 of the different species, and even of the genera. The drawings of 

 these delicate parts (Plate XVI. figs. 8-10) will explain their shape 

 and formation much better than any amount of description. 



We meet with a similar but much more complicated formation 

 in the tongue of the Meliphagi7ice. Their os entoglossum ends in 

 two cartilaginous filaments ; and the whole tongue shows a truly 

 dichotomous arrangement, which towards the tip leads to the forma- 

 tion of the well-known " brush." 



The second drawing exhibited (fig. 2, p. 65) shows a series of 

 sections through the tongue of Ptilotis carunculata. 



Stage A corresponds with that in Cinnyris ; but in the next 

 stage we see that the median unpaired and the two lateral inwardly 



%J. 



D E F 



Sections of the tongue of Ptilotis carunculata. 





directed outgrowths of the ventral sheath are much stronger than 

 in the corresponding regions of the tongue of Cinnyris. In 

 stage C the approaching separation into a right and left half is 

 indicated by a deep fissure/, and we observe similar fissures in the 

 two lateral outgrowths (ff and h). The lateral horns (/) of the ventral 

 sheath do not become reduced, but are preserved ; and the dorsal 

 sheath (d) forms a thin and only half-cornified lining to the cavity 

 or open groove on the upper side of the tongue. In front of this 

 section, corresponding to the level D in fig. 2, the separation into 

 a right and left half is complete, and the remnants of the dorsal 

 sheath are seen in a similar position to that which they occupy in 

 fig. 1 D, in Cinnyris. 



Proc. Zool. Soc 1883, No. V. 5 



