[Proc. Roy. Soc. Victoria, 23 (N.S.). P'''- I- I^'IO-] 



Akt. V. — New or Little-Known Victorian Fossils iv the 

 National Museum. 



Part XI. — On an Impression of a Bird's Feather in the 

 Tertiary Ironstone of Redruth, Victoria. 



By FREDK. chapman, A.L.S., «fec. 

 (Palaeontologist to the National Museum). 

 (With Plates IV. and V.) 

 [Read 26th May, 1910.1 



Introductory. 



^"■08811 remains of birds, compared with those of other animals, 

 are of rare occurrence. The reason for this is not far to seek. 

 The bodies of birds, on account of their lightness of build, 

 readily float, and are therefore more liable to disintegrate and 

 decay before they can arrive at conditions tending to preser- 

 vation by being sealed up in mud or silt. Moreover, their 

 bones, with more or less easily attacked pneumatic structure, 

 are placed at considerable odds compared with the more solid 

 bones of mammals, or even of most reptiles. From such floating 

 or decaying bodies the feathers soon tend to become detached ; 

 and these, also, have small chance of being preserved, unless 

 caught amidst water-logged masses of leaves. Hence it is that 

 most of the records of fossil feathers are from lacustrine, estua- 

 rine or shallow-marine accunmlations, where they are generally 

 associated with plant- and insect-remains. The rocks in which 

 feathers have been found are for the most part of fine-grained 

 texture, and comprise iron-stone, originally ferruginous mud or 

 ooze, and gypseous and carbonaceous clays in the lacustrine 

 series ; and, more rarely, the inpalpable marly deposits of 

 marine origin found in liavaria (Solenhofen- or Lithographic- 

 Stone). 



