A description from Coflein implies that Llech Ciste is interpretted, not as a stone row, but as a standing stone with other (suspect?) stones around it:
A white quartz stone, 2.8m long by 1.0m wide by 0.8m thick, now semi-recumbent, having other stones, or boulders, associated with it. The site is no longer considered to represent the remains of a burial chamber.
The name Llech Ciste implies a single stone, the word ‘llech’ being singular. Presumably the word ‘ciste’ is to do with the site being interpretted as a burial chamber.
The eight figure grid reference for the site is SN51422832, and the National Primary Record Number (NPRN) is 303977.