1867.] PROF. HUXLEY ON THE CLASSIFICATION OF BIRDS. -457 



-*- 1. The Charadriomorph^id. 



The rostrum is always elongated and comparatively slender. The 

 base of the skull possesses narrow and prominent basipterygoid pro- 

 cesses. The maxillo-palatines are concavo-convex and lamellar, never 

 swollen or spongy. The angle of the mandible is produced into a 

 slender and abruptly recurved process. 



The sternum is sometimes singly, but, more usually, doubly 

 notched. 



The hallux, always small, is sometimes absent. 



The phalanges of the anterior toes diminish in length from the 

 basal to the penultimate. 



The pterylosis of this group, which nearly corresponds with the 

 l)ressirostral and longirostral Grallee of Cuvier and with the Limicolce 

 and Sco/ojjacincB of Nitzsch, has been carefully described by the 

 latter writer, who remarks that, " next to the Passerince and Galli- 

 nacece, this group appears to present the smallest pterylographic dif- 

 ferences " *, and that in the form of the tracts it closely approaches 

 1* Sophia and Grus. 



The feathers always cease above the suffrage, though sometimes 

 the bare area is very small ; and the webs between the front toes 

 are large only in Recurvirostra, 



— 2. The Geranomorph^. 



The rostrum is relatively stronger than in the preceding group, 

 and may even be short and arched. 



Basipterygoid processes are absent (ex. Gt'us antigone). 



The maxillo-palatines are concavo-convex and lamellar. 



The angle of the mandible is truncated. 



In the typical groups the sternum is comparatively narrow and 

 elongated, and may be deeply notched or entire. 



The feet vary greatly, but the toes are never completely or even 

 extensively webbed ; and the ratio of the length of the phalanges 

 of the toes is as in the preceding division. 



A greater or less space above the snffrago is devoid of feathers ; 

 but there appears to be nothing characteristic about the pterylosis 

 of this group. 



I consider the Cranes and the Rails (between which Psojihia and 

 Rhinochetus are intermediate) the typical forms of this group. 



Otis connects it with the Charadriomorphse, and Dicholophus with 

 the birds of prey ; but it is a question whether these two genera 

 may be better included in this group, or made types of separate 

 groups. 



■r 3. The Cecomorph^. 



The rostrum varies greatly in shape ; but is very generally com- 

 pressed from side to side, and hooked at the extremity. 



ProceUaria gigantea alone has presented basipterygoid processes. 

 Tlie maxillo-palatines are usually lamellar and concavo-convex as 



* See Nitzsch, ' Ptet ylography ' (Hay Society's Edition), p. 134. 



