INTRODUCTION. 



By one of those accidents " which," as a friendly reviewer in the 

 ' Athenaeum ' observes, " indicate the personality of Ahriman," the slip 

 of MS. containing the Palamedeiformes appears to have been mislaid or 

 destroyed, and never to have reached the printer. This omission not 

 only escaped my own observation, but that of every one of the kind 

 friends who were looking over my proofs. 



I have, therefore, to ask those who possess the first volume of this 

 ' Hand-list ' to insert the annexed page in its proper place in Vol. I. 

 (p. 205), and to alter the numbers of the Orders from the Anseriformes 

 onward. The Order Strigiformes, with which the volume ends, should 

 have been numbered XXVII. instead of XXVI. 



It will be noticed that I have reverted to the old-fashioned name of 

 Cypselus for the Swifts, instead of Apus of Scopoli. The latter name 

 having been adopted by Mr. Hartert in the ' Tierreich,' has been 

 empk>3 r ed by most recent authors who have followed the example of this 

 great authority on the Cypselidce. Professor Eay Lankester has, however, 

 drawn my attention to the inconvenience which would occur from the 

 adoption of Apus in Ornithology, as it is a well-known name in Crus- 

 tacea, and has been in constant use for more than a century. Laying 

 aside its ancient occurrence in the work of Schaeffer, as being pre- 

 Linnean and inadmissible, we find that Scopoli used both Apos and Apus 

 in the same work, ' Introductio ad Historiam naturalem,' 1777. Apos is 

 assigned to the Crustacea on p. 404, antedating Apus for the Swifts on 

 p. 483 of the same work. The only question to be considered is whether 

 Apos and Apus mean the same thing, and whether Scopoli did not insert 



