FROM THE SOCIETY S GARDENS. 



665 



Ibidcecus flavus, sp. n. 



This species does not form part of the collection on which the 

 report is based, but for the purpose of comparison it is useful to 

 include it here, especially as many specimens — male, female, and 

 larvfB — are available for study, being part of a valuable con- 

 signment of Mallophaga presented to the British Museum by the 

 Hon. N. 0. Rothschild. 



I. flavus was collected on Plcdihis Jlavipes (Gould) (the Yellow- 

 billed Spoonbill of Australia) from " Serpentine, Melbourne," on 

 August 3rd, 1911, the label being endorsed "A. Coles." It is a 

 handsome yellow parasite, recognisable by the shape of the pre- 

 antennal region of the head, Avhich is longer than in /. platalece 

 and more truncate at the front margin, but not so long as in 

 /. Jdans and the other members of the long-headed section of the 

 genus. The male genital plate is also a ready means of identifying 

 this form (text-fig. 16). 



Text-figfure 16. 



Ibidoecusjlavus. Male genital mark. X 90. 



External form. — Male. Head (text-fig. 17): Large; pre-- 

 antennal region elongate, each signatural plate long, parallel- 

 sided. Line of the temple from the antenna to the anterior 

 lateral angle of the pronotum very convex. Occipital line straight, 

 an exoccipital thickening on each side. Two dark brown, slightly 

 diverging rafters run across the roof of the skull. A small gular 

 plate present, in front gracefully narrowing to an acute apex. A 

 single median occipital apodeme running into the prothorax. 

 Tentorium absent. Thorax : Much narrower thnn the head, 

 almost parallel-sided and rectangular. Spiracle opens laterally 



Proc. Zool. Soc— 1916, No. XLYI. 46 



