Sclatek on the Systema Avium. 29 



Sectio TracheophotuB. 



xix. Dendrocolaptida;. xxii. Tyrannida-. 



xx. Pteroptochida-. xxiii. Cotingidte. 



xxi. Formicariida'. xxiv. Phytotomidae. 



Ordo FlSSIROSTRES. 



i. Momotidae. vi. Trogonida?. 



ii. Todida?. vii. Caprimulgida;. 



iii. Alcedinida-. viii. Cypselidae. 

 iv. Galbulidas. ix. Trochilidas. 



v. Bucconida?. 



Ordo Scan so res. 

 i. Cuculidae. iv. Picidas. 



ii. Rhamphastidae. v. Psittacidae. 



iii. Capitonida;. . 



This arrangement of the three first orders of birds I employed 

 until 1S72, allowing the Accipitres to succeed, and the remaining 

 orders to follow, according to the Gravian system. But in 1872 

 it was necessary to decide what arrangement should be employed 

 for the remaining orders in the list of Neotropical birds ('No- 

 menclator Avium Neotropicalium') which I was then preparing 

 together with Mr. Salvih.* In the mean time the famous inves- 

 tigations of Prof. Huxley on the bones of the palate in the class 

 of birds had taken place, and an entirely new arrangement of the 

 class, consequent upon these inyestigations. had been promul- 

 gated. Having long entertained serious doubts as to the validity 

 of the Grayian system, especially as to the groups associated to- 

 gether in the orders Grallae and Anseres. I was pleased to find 

 an alternative which had the sanction of high authority. Prof. 

 Huxley had commenced his - 'Systema"f with the lowest and 

 most reptilian birds, and had ended it with the highest and most 

 specialized. But it seemed to me that, by exactly reversing this 

 arrangment, I should obtain a scheme which would not very far 

 deviate from that which I had already employed as to the first 

 three orders, and would ofier many improvements on the Gravian 

 system in the remainder. In the introduction to the ' Nomencla- 

 tor,' accordingly, I gave the subjoined scheme as that which I 

 proposed to employ for the general arrangement of living birds, 

 dividing them into 21 orders, as follows : — 



* [The arrangement adopted in the ' Nomenclator' is entirely Mr. Sclater's. I was 

 forced to desert my colleague when I visited Central America in 1873-4, a portion only 

 of this work having been then printed and the Introduction unwritten. — O. S.] 



t P. Z. S. 1867, p. 456 



