One can check that for transversal Lagrangian submanifolds $L_{1}$ and $L_{2}$ as above, the Maslov index at any $x\in L_{1}\cap L_{2}$ is equal to the Morse index at $p^{\vee}(x)$ of the smooth Morse function $f_{1}-f_{2}:Y\to{{\bf R}}$ such that locally near $x$ one has $L_{i}=graph\,(df_{i})\,(mod(T_{Y}^{{\bf Z}})^{\vee}),i=1,2$.