THE HEADMISTRESS Angela Thirkell Knopf ($2.50).
Since 1936 talented Angela Thirkeil, who is. as stylistically languid as her Pre-Raphaelite grandfather Edward Burne-Jones and as staunchly British as her cousins Stanley Baldwin and the late Rudyard Kipling, has made hay in the fictitious fields of Barsetshire the mythical English region created by Victorian Novel ist Anthony Trollope. In a series of novels (including the best-selling The Brandons and Northbridge Rectory}, Author Thirkell has peopled Barsetshire with 20th-Century "descendants" of Trollope's squires, rural deans, bluebloods, housemaids and self-made men all...