Sheep Bot Fly
The full grown larva of the Sheep Bot Fly (Oestrus ovis) is a fly in the Oestridae family of bot flies and is known as a major pest in the Australian sheep industry. 'b' shows anal appendages.
William Dwight Whitney The Century Dictionary: An Encyclopedic Lexicon of the English Language (New York, NY: The Century Co., 1911)
Courtesy the private collection of Roy Winkelman