PKEFACE. 



The numbers of the species of the nine families treated of in the 

 twenty-third volume, and of the specimens at present in the Col- 

 lection, are as follows : — 



Species. Types. Specimens. 



Eallidffi 187 39 2471 



Heliornithida) . . 4 1 45 



Aramidse 2 . . 28 



EurypygidiB .... 2 . . 26 



Mesitidae 1 . - 1 



llhinochetidoD . . 1 . . 3 



GruidjB 19 1 143 



Psophiidaj 6 1 13 



Otididtc 30 7 217 



252 49 2947 



In the first category 29 forma are included which are considered 

 by the author to be of onlj' subspecific rank, while 33 species 

 and subspecies are still unrepresented in the Collection of the 

 Museum. Beside the 49 types of recognized species, the Collection 

 contains 27 other typical specimens which are now relegated to 

 the synonyms. 



As in the preceding volumes, the series of specimens of the 

 American and Indian species are derived chiefly from the Hume, 

 Tweeddale, and Godman-Salvin Collections ; but they have been 



