INTRODUCTION 97 
that, disencumbered from both the last two, 1s eminently natural, and 
easily dealt with. A great break then occurs, and the new serics is 
opened by the Eleventh “ Order,” Columbe, with 3 Families, Carpophagide, 
Columbidz and Gourde, “or perhaps a fourth,” Didunculide,1—the Dopos 
being “held to belong to quite a separate section of the order.” The 
Twelfth “Order” is formed by the Pterocletes [!] (SanD-Grousg) ; and 
then we have the very natural group Gallinz ranking as the Thirteenth. 
The next two are the Opisthocomt and Hemipodit for the Hoacrzin and 
the Turnicide (HEMIPODE) respectively, to which follow as Sixteenth and 
Seventeenth the Fulicartz and Alectorides—the former consisting of the 
Families Rallide (Ratt) and Heliornithide (Finroot), and the latter of 
what seems to be a very heterogeneous eompound of 6 Families—Aramidex 
(Limpxiy), EHurypygide (SUN-BittERN), Gruide (CRANE), Psophitde (TRUM- 
PETER), Cariamidz (SuRIEMA) and Otididex? (Busrarp). It is confessedly 
very puzzling to know how these varied types, or some of them at least, 
should be classed ; but the need for the establishment of this group, and 
especially the insertion in it of certain forms, is not explained by the 
author. Then we have ‘Orders” Highteen and Nineteen, the Limicola, 
with 6 Families, and Gavizx, consisting only of Laridx (GuLL), which 
taken in their simplest condition do not present much difficulty. The 
last are followed by Yubinares (PETRELS), and these by Pygopodes, to 
which only 2 Families Colymbidz (Diver) and Alcidx (Auk) are allowed— 
the GreBes being included in the former. The Jmpennes (PENGUIN) form 
the Twenty-second, and Crypturt (TiIvamov) complete the Carinate Sub- 
class. For the Ratitez only three “Orders” are allotted —Apteryges, 
Casuariz and Struthiones., 
As a whole it is impossible not to speak well of the scheme thus 
sketched out, so far as materials for it existed ; and, in 1884, an attempt 
was made (Hncycl. Brit. ed. 9, xviii. pp. 43-49) to indicate those points 
in recent Classifications which then seemed to have been established on a 
pretty sure footing, though therein the writer had no intention, any more 
than he now has, of inventing (as has sometimes been supposed) a new 
arrangement of Birds. He did, however, try to shew that some positions 
which had been taken up could not be maintained, and among other things 
that the ‘‘ Subclass ” Odontornithes, founded as above mentioned (page 87) by 
Prof. Marsh, was artificial, for, while Birds yet retained the teeth they 
had inherited from their Reptilian ancestors, two remarkable and, in the 
opinion of many, distinct groups of the Class had already made their 
appearance, which two groups persist at the present day in the Aves 
Ratitze and Aves Carinatz long ago recognized by Merrem. Furthermore, 
while the Ratite type (Hesperornis) presents the kind of teeth which 
indicate (in Reptiles at least) a low morphological rank, the Carinate 
type (Ichthyornis) is furnished with teeth set in sockets and shewing a 
higher development. On the other hand this early Carinate type has 
vertebree whose comparatively simple, biconcave form is equally evidence 
of a rank unquestionably low; but the saddle-shaped vertebre of the 
1 In the eighth edition of the List of Vertebrated Animals in the Zoological 
Gardens, which, being published in 1883, may be taken as expressing Mr. Sclater’s 
later views, the first two Families only are recognized, the last two being placed 
under Columbide. 2 Wrongly spelt Otide. 
