( 336 ) 



albigularis and Julvifacies. It is inconceivable why this was done, as these last 

 two forms are as typical Abrornis as schisticeps and superciliaris. Evidently 

 Bianchi was not acquainted with these forms, and wrote about them not from 

 antojitic knowledge and study, but only from what he had found in other books. 

 This shortcoming is apparent in various instances in his article. Had he actually 

 examined all these forms, such an experienced, keen-eyed and careful ornithologist 

 could not have made such mistakes. It is, in my opinion, a grave error to 

 write and to make firm statements about forms one does not know, unless this is 

 unavoidable. Of course, when writing a monograph about a certain family, say a 

 volume of the Catalogue of Birds or of the Tierreick, all named forms must be 

 mentioned, and, although it is impossible to examine every one of them, some 

 conclusion must be arrived at. Otherwise it is, as a rule, wiser not to say anything 

 about a species not known to the writer. 



A greater difficulty than the limitation of the genera Abrornis and Tickellia is 

 the differentiation between the genera Phylloscopus and Cryptolopha. Both have 

 twelve rectrices and the bills in both vary very much. Formerly the former genus 

 was placed among the Sylviidae, the latter among the Muscicapidae. The result 

 has been that certain forms, which are neither the most typical Phylloscopi nor very 

 typical ( 'rgptolophae, were partly placed in the one, partly in the other genus ; 

 this has been done frequently. Thus, to quote ouly one example, Phylloscopus 

 trochiloides has always been placed in this genus (respectively Acantlwpneuste, a 

 subgenus not recognised by me) ; while a form merely differing by its much brighter 

 coloration and perhaps slightly shorter wings, ricketti of Slater, has been described 

 as a Cryptolopha, and has quietly rested in the latter genus until now. There are 

 naturally several ways to get over our difficulty : either to form some more genera 

 for the less typical and somewhat intermediate forms, or to unite Cryptolopha and 

 Phylloscopus, if we cannot admit the status quo — I mean, if we cannot be content 

 with the last-named two genera. I have considered all mauners. Pleske, Gates, 

 and Sharpe {Handlist, iv.) have taken the first-named course, distinguishing between 

 Phylloscopus, Acanthopneuste, Oreopneuste, Reguloides and Cryptolopha. This 

 arrangement is, however, unsatisfactory, because of great inconsistencies iu it : for 

 example, if all these genera are admitted, why then is sibilatrix, a bird quite as 

 different from a Chiffchaff or "Willow-wren as borealis, left in Phylloscopus s.s. ? 

 There are no sharp limits for these genera, and the inevitable result is that certain 

 forms are placed by one writer iu this, by another iu another genus. Therefore, 

 this way out of the difficulty is not advisable. If uniting Phylloscopus and Crypto- 

 lopha, on the other hand, we find most divergent extremes iu such an assembly, 

 and, I believe, we can still admit the two groups, as between the widest-billed 

 Phylloscopus and the nearest Cryptolopha there is still a gap, the latter having, 

 combined with a wider bill, stronger rictal bristles, and, as a rule, a longer first and 

 shorter second primary, while the former has a narrower bill — though varying 

 greatly from the narrow beak of a Ph. tristis to the wide one of a vuignirostris, 

 occipitalis, trochiloides, or of the small-sized Reguloides group — and usually a 

 less-developed first and more prolonged second primary. Under this arrangement 

 we have to place iu the genus Phylloscopus, iu addition to forty-one palaearctic 

 forms treated of iu my book, Die Vbgel iter put. Fauna, i. p. 501 lb, the following 

 forms : Ph. ricketti, tricirgata, cantator, kinabalmnsis, olicacca, presbytia, sarosi- 

 norum, Jloris, water stradti, everetti, giulianetti,Julviventris, and nigrorum ; while in 

 Cryptolopha we place : burkii, tepkrocepiialus, valeniini, intermedia, affinis, xantho- 



