These are archives generated by LArc, the predecessor to LHA, which uses the
-lz5- compression algorithm.  Found in larc333.exe (self extracting archive):

    http://ftp.riken.go.jp/pub/pc/simtelnet/msdos/arcers/larc333.exe

lz4.lzs             - Archive containing uncompressed (stored) file.
lz5.lzs             - Archive containing -lz5- compressed file.
sfx.com             - Self extracting LArc archive.
long.lzs            - Archive containing a large compressed file.
subdir.lzs          - Archive containing subdirectories.

