Hello Linda,
Welcome to Conch-L.  I hope you find it both enjoyable and useful.
The two shells you mention are quite familiar.  The first one, if
it's what I think it is, is not a Latiaxis at all, though I have seen
it listed as a Latiaxis on exporters' and wholesalers' lists several
times, and occasionally even on retail dealers' lists.  The correct
genus name is Lataxiena, not Latiaxis (obvious where the confusion
comes from).  It is in the family Muricidae (Murex family).
Lataxiena fimbriata Hinds has a fairly wide range in the western
Pacific, and "Formosa" (now Taiwan) is well within its geographic
range.  I have specimens from there.
Your other shell won't be found in a "seashell" book, because it is
not a seashell - it is a land snail, Acavus haemastoma L., from Sri
Lanka (formerly Ceylon), where it is very common.
Regards,
Paul Monfils