Cycle lengths [in networks]

The lengths of the shortest cycles (girths) of the networks on page 479 are (a) 3, (b) 5, (c) 4, (d) 4, (e) 3, (f) 5, (g) 6, (h) 10, (i) ∞, (j) 3. Note that rules of the kind discussed on page 508 which involve replacing clusters of nodes can only apply when cycles in the cluster match those in the network.