282 PEOFESSOE W. K. PAEKEE ON THE 



is as broad as in Pants : the outer margin is gently excavated ; and the nerve-passage 

 is simple, and not separated into two for the olfactory and the orbito-nasal as in Parus. 

 There is no lacrymal bone. 



Altogether this bird belongs to the Paridse ; it differs from them in precisely the 

 same manner as Southern birds do differ from Northern, although it has come from 

 24° 30' north of the equator. This will be conceded to me — that the distribution of types 

 must, of necessity, be marked by an undulating line. Southern forms passing north, and 

 Northern forms going south, to some considerable extent. 



I am the more confident in calling this bird a Notogeal type of the Paridse by 

 what, in the most unexpected manner, I see in a Passerine bii'd from Bahia, in Brazil. 

 The skull of that bird will now be described ; and in it we shall see a bird the size of 

 a Nuthatch, with the characters of Suthora, but still more generalized. 



Example 58. Skull of Cyclorhis, sp. % Family Vireonidse. Group Oscines. 

 Habitat. Bahia, Brazil. 



It is not possible to see this bird, from 38° 59' south of the equator, on the eastern 

 coast of South America, and find in it, as it were, the large prototype of the little 

 Chinese bird just described, without a sense of hopelessness with regard to the discovery 

 of the laws of the geographical distribution of birds ^. 



The skull of Cyclorliis is altogether lighter and more pneumatic than that of the 

 little Suthora ; this is a constant thing amongst even the highest families of birds, 

 the pneumaticity agreeing with the size of the bird. Also, on the whole, it is less spe- 

 cialized as to the height, shortness, and strength of the rostrum (Plate LI. figs. 4 & 6) ; 

 this agrees with the fact that the larger is the more generalized type. But their likeness, 

 on the whole, is incontestable, and would be seen at once by the most inexperienced 

 anatomist ; the palatal and lateral views (figs. 5, 6) speak for themselves ; and the 

 greatest contrast between the two arises from their difference in relative length, or 

 degree of prognathism. 



This large archaic Tit shows the same want of typicalness in its pterygoids [pg) as does 

 Suthora, only in a greater degree. The epipterygoid {e.pg) is not more pronounced 

 than in a Fowl, being merely a low triangular crest strapped to the fore edge of the 

 quadrate. This crest is the hinder part of a steep ridge which runs along the top of 

 the bone, and ends in front in the usual "spatula." Great strength of the pterygoid 

 muscles is here suggested. Altogether this is a strong-faced bird, but not specialized 

 to such activity and power of movement as in Suthora. Whatever was the size of the 

 mesopterygoid segment, it is lost now on the postpalatine plate (pt.pa) : this latter part 



' 'the skull here described was taken from a skin put into my hands by Osbert Salvin, Esq., F.E.S. I am 

 writing in total ignorance of the views of zoologists with regard to this type ; so that my thoughts are free 

 ■whilst tracing its relationship. 



