My house was built in 1930 and is a conventional foundation. I want to move the toilet 90 degrees and 1 foot from where it is now. While inspecting the plumbing under the house, I noticed that the toilet appears to have it's own connection to the sewage system separate from the tub and sink. The tub and sink appear to have their own connection to the sewage system as well. The toilet does not appear to be vented, but the tub and sink are. Is this a correct plumbing configuration and can I move the toilet to it's new location without a vent? Is it customary to have separate tie in's to the sewage system?

Thanks