278 PEOFESSOK W. K. PAEKEB, ON THE 



zation of their skull, then it will not be hard to draw unto them such forms as show, 

 more or less, a like state of that part of theii- build. 



That which is suggested by the outer form and by the living bird is that this small 

 type has large brain-power, and indubitable energy and courage, combined with great 

 bodily strength for so small a creature. The skull is large and wide, and the face short, 

 conical, and strong ; these two regions are so hinged on each other that they admit of 

 as much motion as in the highest Finches and even the Parrots. On the whole, the 

 palatal framework is as strong as in the Finches ; and some of the specializations are 

 similar; but the Tits are further removed from them than from their soft-billed 

 allies. 



The pterygoids (Plate LI. fig. 1, pg, e.pg) are stout and straight, with a lobate epi- 

 pterygoid. The dilated anterior end is of much less extent than in either the hard- 

 billed or soft-billed songsters. So also the segment given off, the mesopterygoid, is much 

 smaller ; and, as in the Parrots, the pterygo-palatine arcade embraces the skull-base 

 very little : this is a clear and good Parine character. This part is also still further 

 differentiated from what is normally Passerine; for where the anterior spike of the 

 pterygoid breaks off to form the mesopterygoid, the result is two new centres ; the fore- 

 most of these (fig. 1 a, ms.p^), corresponding to the normal segment, is a small trian- 

 gular grain of bone, whilst the larger heart-shaped piece (fig. 1 A, ms.pg") is behind the 

 steep top of the pterygoid, which is thus wedged in between its own ^lial segments. 

 Also it is to be noted that these parts continue separate for a long time, and do not 

 behave like the very temporary segment of the ordinary Passerines. 



The palatines are more like those of the thin- than of the thick-billed kinds ; but 

 they are as strong as in the latter. The transpalatine part (figs. 1 & 1 a, tpa) is 

 roughly triangular, and passes, by a broad isthmus, with a short ethmo-palatine plate, 

 into interpalatine snags, which are blunt and pass into steep postpalatines (figs. 1,1a, 

 ipa, e.pa, iit.pa). From the broad part proceeds the long, sinuous, broad praepalatine 

 (pr.pa) ; the breadth, with the length, of this bar is another safe Parine character. 

 The setting-in of the fore end of this bar into the short rostrum is very definite ; but it 

 coalesces with the prsemaxillary, and therefore falls short of the Grosbeak and Parrot 

 in this part of the cranio-facial hinge. But the prsemaxillary of this bird is, perhaps, 

 the part least likely to be mistaken for that of any other bird ; it forms its hinge at 

 quite another point than in the Grosbeak and the Parrot : they include the maxillaries 

 in the rostral mass ; the Tit excludes them (PI. LI. fig. 1, d.px, mx, mx.p). The form of 

 the coalesced prsemaxillaries is metamorphosed greatly ; and by the absorption of their 

 long processes a very characteristic bone is found in the adult ^. 



In a three-fourths ripe embryo of a Tit (see my paper referred to in footnote) the 

 prsemaxillaries are fast ankylosing together : they are very Reptilian in their shortness ; 

 and their dentary and palatine processes {op. cit. fig. 4, d.px, p.x) are very small spurs, 



' For the early stages of this Tit's skull, see the ' Monthly Microscopical Journal,' Jan. 1873, p. 6, pi. ii. 



