VI PREFACE. 



and to be employed only for our convenience, and names 

 should not be bestowed when there is only a single species to 

 represent them. In order to grasp my critic's full meaning, I 

 consulted the published "Catalogue" of his collection, and there 

 I found the whole of the Thrushes placed under the genus Tur- 

 dus, though this is exactly the instance he quotes in his critique 

 in which these birds ought absolutely to be classified under the 

 heading of the two genera, Turdus and Merula. Tiien, in order 

 to determine what characters Canon Tristram considered to be 

 of generic value in the only instance in which he has shared 

 my crimes with me, I find that the Seychelles Scops-Owl was 

 considered by him to be worthy of a new generic name, Gym- 

 noscops, from the fact that " its ear-tufts, if any, are only rudi- 

 mentary, and its tarsi wholly unfeathered, excepting a narrow 

 line for about a quarter of an inch down the front of the tar- 

 sus, while the back of the joint is entirely bare." Slender dis- 

 tinction enough, as the describer himself seems to think, for 

 he adds : " I venture to think that these differences entitle 

 it at least to sub-generic, if not generic, rank." After this ad- 

 mission of what constitutes a generic or sub-generic difference, 

 I am surprised that Canon Tristram should have ventured to 

 stigmatise as "new fangled," "absolutely capricious," <Scc., 

 genera which are founded on quite as strong characters as he 

 allows to be sufficient in his own case. 



Pie then proceeds to make a somewhat startling comparison 

 as to the number of generic names which figure in my volumes 

 of the "Catalogue of Birds," viz., io8, as compared with 

 those written by my coadjutors, Mr. Seebohm and Dr. Gadow, 

 "neither of whom invented a single new genus," Mr. Osbert 

 Salvin (one), Mr. Edward Hargitt (four). Captain Shelley (five), 

 Mr. Ogilvie-Grant (six), Count Salvadori (twelve),* " while Dr. 

 Sharpe in lo^ volumes has favoured us with io8 new genera. 

 It is obvious that the * genus-standard ' of Dr. Sharpe must be 



* To have been quite fair, Canon Tristram should have added two new 

 genera of Swifts (out of nine !) published in Mr. Hartert's half volume. 



