It sounds like your cat has tapeworms. They will look like white rice or sesame seeds after they are dead.
You can give a call to your vet and describe the worm to him. They will usually give you medication without having to see the cat.
Keep in mind that tapeworms come from fleas so you will want to get some frontline or other flea prevention when you are there.
Over the counter wormers will not work for tapeworms. You will have to get some droncit or drontal from your vet to treat it.
Let me know if you still have questions.