This week's stitch is also known as the "Ridged Spider Web" in Jo Christensen's The Needlepoint Book. This book, which I believe I have featured in the past on the blog, is a marvelous resource. If you do not already own a copy, I would urge you to get one.
Most of the information for this week's stitch is taken from the Christensen book -- pages 353 and 355. Spider webs are an interesting type of stitch. They are two-step stitch, first you need to lay down a foundation stitch and then you stitch over your foundation to create the final look.
Our foundation stitch for the Backstitched Spider consists of what I think of as a Smyrna Cross eyelet. The stitch consists of a plus sign and an "X" however all legs of these stitches meet in a center hole. The plus sign is done across four vertical canvas threads and into the center hole. The cross stitch is done across three canvas intersections and then into the center hole.
Once the foundation has been laid, the next step is to perform the backstitch. Return to the front side of the canvas in a hole that is as near as possible to the center of the canvas but not in the center itself. Go underneath two of the spokes and pull the thread forward. Next go underneath the last spoke for a second time and then underneath the next spoke. Pull the thread forward. Continue working in this fashion -- going underneath the last spoke and the next spoke -- around and around the circle. You should do this until it is not possible to go around again.