Praying Mantis Egg Case

I found this under a boulder and I had a nagging feeling that I knew what it was...I just couldn't remember. So I sent the image to my Bugographer friend, Phil Huntley-Franck and he reminded me of what it is: a mantid egg case!

Nearly 20 years ago I purchased a case like this and put it in a jar to hatch. A week or two later the jar was BRIMMING with thousands of the most adorable praying mantis babies! I took them out into the garden and released them with hopes to see some of them again if I looked. However, hard as I tried, I never did find a single one of them!