Yeah, it does look like a Tape worm. That is really gross. I've never heard of worms in eggs. You should deworm them again tape worms, which may need a different treatment then is used for other types of parasites.
We've had tape worm problems in our house. They would crawl out of the back-end of our dogs and cats and be on the furniture, crawling around! These were the smaller segments, however, that's a pretty large piece.
Yuck.
It could just be a piece of stuff that the chicken laid also. Meat chunks in eggs can be found, but these look nothing like that.
You should worm them all with Valbazen. 1/2cc by mouth for reg sized hens, 1/4cc for bantams. Repeat in 10 days. Pitch eggs until 14 days after the last dose, I think. Hopefully dawg53 can chime in. He's super smart with all things worm related.
Good luck
Poultry tapeworms are flat and segmented. They are difficult to get rid of in chickens. The head (scolex) buries itself deep into the intestinal lining. When it grows, segments break away and are excreted in feces. They look like white rice and they work their way into or onto the soil. Each segment contains hundreds of eggs. The eggs are eaten by insects. Then the insects are eaten by our feathered friends. Their lifecycle starts all over again. Telltale signs of tapeworm infection are the white rice like segments in feces. http://www.bing.com/videos/search?q...&mid=5D50CB8F782958C4161D5D50CB8F782958C4161D
Here's a pic of tapeworm segments in feces: