CHAPTER XIII. 

 Subclass II. Aves Terrestres, or Cursores. 



Terrestrial Birds. 



This series embraces all living birds between the Col- 

 and the LameUirostres, with the probable exception 

 of the Struthionidce and their allies. They are united more 

 bv analogous connection, than by any particular morpho- 

 logical affinity. There is certainly greater structural 

 diversity existing among them, than there is between some 

 of them and those birds which occupy the confines of the 

 Insessores and the Natatores. The gallinaceous birds 

 shade directly into the columbine, on the one hand, while 

 the Grallatores, through the flamingoes, are perfectly united 

 with the Natatores, on the other. The legs are long or 

 strong as compared with Insessorial birds, and the knee 

 and lower thigh free as compared with the Natatores. 

 The hallux is both abbreviated and elevated in the gener- 

 ality of cases, but often entirely wanting ; while the anter- 

 ior toes are usually provided with a basal web, frequently 

 cleft, 'and sometimes lobed, or completely webbed. Except- 

 ing the Struthionidce, this series comprehends two com- 

 monly accepted orders. 



Order GallinED. Gallinaceous Birds. 



The birds belonging to this order are more or less ter- 

 restrial. The legs are of moderate length, and rather 

 strong; the toes four, rarely varying therefrom, three of 

 which are anterior, generally united by a web at the base, 

 and occasionally free ; and one posterior, which is some- 

 times wanting, but usually short and elevated. The tibia? are 



