Victorian Trellis Doily - End of 3rd Round / Start of 4th Round
All videos related to this design can be found in this playlist:
This vintage pattern can still be found in print but is also freely available online as it is now out of copyright. You can find it on pages 15-17 of the Priscilla Tatting Book no. 2, available here:
On my blog, you can also find a written explanation of the first round of the pattern with photos which you may find useful in complement to the video: