The aim of this proposal is to investigate fossil dust shells around
 members of the class of R CrB stars, following the discovery, using
 IRAS, of a very large cool dust shell around R CrB itself, and
 possibly one around SU Tau. The parameters of the R CrB dust shell
 are very uncertain, but they are not inconsistent with the
 evolutionary scenario for R CrB. The original IRAS data suggested
 that not all R CrB stars might have this cool fossil shell, so that
 a more sensitive survey of the stars is needed. Since the fossil
 shells were only visible at 60um and 100um with IRAS, only ISO can
 further investigate the phenomenon. The dust temperature was estimated
 at 25 - 30 K. The size of the fossil shell around R CrB was about
 20 arcmin, so that mapping is needed.