What is the command syntax on a PIX515e for allowing access to the range to addresses 150.147.1/24?
The clarification that you provide is helpful. If you want to allow that range of addresses access inbound then you would add a line like this to the inbound access list on the firewall :
access-list permit ip 188.8.131.52 255.255.255.0 any
This would give Sirsi access to all of the IP addresses in your network. If the library has a certain range of IP addresses you might change the "any" to specify the range of library addresses as the destination.