( 280 ) 

 ON SOME AUSTRALIAN FORMS OF TYTO. 



By the H..n. WALTER ROTHSCHILD and ERNST IIAHTERT. 



WE have both always been particnhirly interested in the jrenus Tyto Billb. 

 When Ilartert studied l;his genns in connection with iiis work on the 

 birds of the palaearctic region we looked together through the material of tropical 

 forms in tlie Tring Mnseum. ('oming to the Anstralian ones, we found that our 

 friend Mr. (t. M. Mathews had described not less tliaii eight new subspecies, six 

 alone of I'l/ln notaehollniidiae, which was hitherto supposed to consist of two forms 

 only : T. nordcJinUnniVme novachollnndiae and 7'. nnrueliolbiiidine. castanops, the 

 former being s])r('ad all over Australia, the latter reiireseiitiug it in Tasmania. 

 As we could not make out Mr. Matliews' subspecies from our scanty material we 

 asked him to lend us his specimens, and looked over those in the British Museum, 

 and from our study of this material we come to the following conclusions : 



I. FoiiMS OK Tyto .u.n.i. 

 i. Tyto alba alexandrae Math. 



-Vol-. Zdol. x\x. p. 250 (January 1912— '■ Northern Territory, North Queensland '). 



The anthor says that it differs from T. a. thlicatnlu of (jiieensland, New South 

 Wales, Victoria, and South Australia in its nincii smaller wing, which measures 

 'i^dVt mm., as opposed to 31ii — 34ii mm. in " typ. birds," by which he evidently 

 means T. alha delicatula. The published measurements of Mr. Mathews must be 

 due to an nne.\]ilainable error or sli[), as the wings of a number of 7'. a. delicatala 

 from South Australia and Victoria measure only L'sl — 'V.>A mm., those of his 

 " alexaiidrae " ','8(J — "i'JIJ mm. There is not tlie slightest dilference, either in 

 colour or in dimensions, and " alej:andrae " is therefore a clear synonym of 

 T. a. delifatula. 



II. FunMS OK Tyto xhvaeiiouaxdiae. 



2. Tyto novaehollandiae perplexa Math. 



Nov. Znnl. xix p. 257 (January 1912 — " West Australia, type from East Beverley "). 



The diagnosis is: " Dift'ers from T. it. novaehoUaiidine in its larger size and 

 darker coloration." No measurements are given. 



The type of T. ii. perplexa is a female, with the wing 342 mm. It would 

 seem that Mr. Mathews had not been aware of the fact that in 7'. noraelioUandiae 

 the sexes difler in size, the female being considerably larger, with the wings from 

 2 to 'i cm. longer; nor of the fact that nearly all species of the genns Tyfo vary 

 individually to a great extent, like so many other owls. If he had known these 

 facts he could not have described a female as a new snbspecies because its wings 

 were 2 or 3 cm. longer, or because its nppersidc is a shade richer in colour than 

 most other specimens of what he then considered to be T. iinraelioUandiae, in 

 Jannary 1012. If he splits the species uji into seveu or eight forms, as he did 

 ju April 1912, his perplexa would in any case be the sftiue as his himberli and whitei. 



