On Biembeddings of Latin Squares

A known construction for face 2-colourable triangular embeddings of complete regular tripartite graphs is re-examined from the viewpoint of the underlying Latin squares. This facilitates biembeddings of a wide variety of Latin squares, including those formed from the Cayley tables of the elementary Abelian 2-groups C k 2 (k 6 2). In turn, these biembeddings enable us to increase the best known lower bound for the number of face 2-colourable triangular embeddings of Kn,n,n for an infinite class of values of n.