From size and shape of this fragment, it looks like the salvaged end of a berthe or large collar.
A great study piece that shows all the elements typical of Carrickmacross in a very pretty piece. End is Carrickmacross Guipure, with no net background, and buttonhole stitch covered connecting bars embellished with picots. Net area has a very pretty floral and leaf sprig. Net behind the corner leaf is decorated embroidered with a fancy pattern.
Edge has the typical looping picots.
Condition is very decent, although the fabric is pulling away from the outline, it still would display very nicely.
Size: 8 inches on the sides.