252 PEOFESSOE W. K. PAEKEE ON THE 



figs. 5-8, p. 325) that the skull of the first of these is altogether of a Notogcean type. 

 It differs from that of a common Raven or Rook just as the skull of a Tanager diff'ers 

 from that of a Sparrow, or the skull of SynaUaxis from that of a Redstart. 



These large Austro-cor vines may be called " Gymnorhinidse," from the kind most 

 familiar to us, the Piping-Crow of Australia. 



The principal morphological steps taken by the lowest Coracomorphse above the 

 super-Tinamine Hemipods are (1) the abortion of the " basipterygoids," (2) the deve- 

 lopment of the " transpalatine " spurs, and (3) the dii'ect union of the double vomer 

 with the nasal wall and floor. 



How slight and easy these modifications are only the morphologist rightly knows : 

 the fitness for arboreal life, the diff'erentiation of the syringeal muscles, the arrest of the 

 caeca coli — these and other modifications follow in order. 



Example 28. Skull of Tanagra cyanoptera. 



Habitat. South America. Section Oscines ; family Tanagridee. 



The skull of this species, as of others of its family, although no larger than that of 

 the more robust kind of Finches, yet resembles that of the Old-world Crows quite as 

 much as it does the same region in the lesser typical Conirostres (Plate XL VI. fig. 1). 



The facial apparatus is altogether feebler than in the Fringillidse ; and the palatine 

 bones have the slender directly retral transpalatine spurs of the Southern type. Thus 

 the face at once suggests a frugivorous rather than a graminivorous bird ; the periosteal 

 outgrowths of bone and the strength of the hinges seen in the stouter Finches, whose 

 skulls at once resemble those of the Fowl and of the Parrot, are not seen in the 

 Tanagers. 



Yet these feebler and more generalized skulls are thoroughly Passerine {Coracomor- 

 phous) ; and, as the Fringillidae are closely related through the Larks (Alaudidae), the 

 Titlarks, and Wagtails to the soft-billed songsters (Sylviidae), so the Tanagers are related 

 to New-world forms with slender and yet slenderer bills, such as the Mniotiltidse and 

 Cerebidae (compare Plate XLVI. with XLVIII.). 



The occipital and basitemporal regions {oc.c, b.t) are quite normal, and the parasphe- 

 noidal beam (jm.s) of average strength. The pterygoids (jjg) are long, rounded, pedate 

 in front and having a goodly epipterygoid hook (e.pg) behind. Compared with their 

 counterparts in the Finches, the palatines are frail, the prsepalatine bar is wide (pr.pa) ; 

 the interpalatine ridge is not spiked in front (i.pa) ; the ethmo-palatines (e.pa) are frail 

 shells of bone confluent with the vomerine crura. The main bar narrows towards the 

 transpalatine {t.pa), which is a fine spike, outbowed, and with its apex turned towards 

 the mid line a little. The prsemaxiUary mass is, although broad, rather corvine than 

 Fringilline ; it is grooved sublaterally, and in the middle ; the dentary regions are 

 distinct and cultrate ; the palatine processes are aborted {d, px; p.px). 



Where the latter processes existed in the embryo, a falcate spicule of bone appears, a 



