Sclater on the Sy sterna Avium. 
76 
4 Nomenclator’ Pici, Cypseli, and Coccyges. The order Picariae 
may then be divided into the following six suborders : — 
Families. Families. 
1. Pici 2 4. Heterodactylee .... 1 
2. Cypseli 2 5. Zygodactylae 5 
3. Anisodactylse . . 12 6. Coccyges 2 
The Picarias thus considered embrace altogether about 1600 
species of birds referable, as shown above, to twenty-four families. 
5. Psittaci. 
The Parrots (J^sittaci), annexed by Cuvier and his disciples 
to the Zygodactylae, are now generally allowed to form one of 
the primary divisions of the Carinate, as was first, I believe, 
suggested by Nitzsch in 1829.* The affinities of this ancient 
group to other orders appear to be somewhat remote, but their 
most natural position seems to be between the Picarise and the 
Accipitres. The best mode of subdividing this order has long 
been a matter of discussion, Dr. Finsch’s mode of grouping, as 
well as those adopted by previous writers, being not very satisfac- 
tory. But a flood of light has been thrown upon this subject by 
Garrod’s excellent memoir on the anatomy of the Psittacidae, j - 
and I think we may safely base our arrangement upon the results 
of his observations. This, indeed, I have already done in the 
last edition of the 4 List of Vertebrated Animals living in the 
Zoological Society’s Gardens’ (1879), where I have arranged 
the Psittaci upon the following plan, of which the details are 
taken from Garrod’s investigations : — 
A. Left carotid normal. 
A'. Orbital ring complete 1. Cacatuidce. 
B'. Orbital ring incomplete. 
A". Sternal keel aborted • ... 2. Stringopida . 
B". Sternal keel developed . . 3. PalceornithidcB. 
B. Left carotid superficial ......... 4. Psittacidce. 
All the New-World Parrots belong to the last family. 
6. Striges. 
That the Owls, with so many peculiarties in their organization, j 
should constitute an order separate from the Accipitres I think 
there is little doubt. There is no known intermediate form, un- 
* Obs. de Avium art. carotide communi. 
% Cf Nitzsch, Pterylogr. p. 67. 
f P. Z. S. 1874, P- 5^6. 
