CORRECTION. On p. 392 the Buekenhout diagram in the middle was drawn incorrectly: the double stroke should have been right instead of left. .so Bdiag/A7 ADDITION. On p. 392 add to construction D: `(This construction is discussed in great detail by .SC Calderbank & Wales .[[ Calderbank Wales global code invariant 1982 .]].)' CORRECTION. On p. 396, line $-9$, replace `$(v,k, lam , mu )$' by `$(v,k, lam )$'. ADDITION. On p. 400, bottom, add: `Let $SIGMA sub n sup eps$ be the graph on the hyperbolic points of $PG(n-1,3)$ provided with a nondegenerate symmetric bilinear form with discriminant $eps$, adjacent when perpendicular. .SC Pasechnik .[[ Pasechnik 1993 locally 3-transposition .]] shows that $SIGMA sub n+1 sup eps$ is the unique connected locally $SIGMA sub n sup eps$ graph for $eps = +1$, $n >= 6$ and for $eps = -1$, $n >= 7$. The example in this section shows that there are at least two connected locally $SIGME sub 6 sup "\(mi"$ graphs (and Pasechnik announces that there are precisely two).' ADDITION. On p. 412, Remark (iii), add: `For a characterization as locally polar graph, see .SC Weiss & Yoshiara .[[ Weiss Yoshiara 1990 geometric .]].' ADDITION. On p. 412, add Remark (iv): `A. Juri\*Vsi\*'c, J.H. Koolen & P. Terwilliger proved that any graph with the parameters of the Patterson graph is locally strongly regular [pers.comm.]. Indeed, we have $(1 + b sup \(mi )(1 + b sup \(pl ) + lam <= ( lam + 1 + b sup \(mi )( lam + 1 + b sup \(pl ) / k$ with equality only if the local graph is strongly regular (with eigenvalues $- 1 - b sup \(mi$ and $- 1 - b sup \(pl$). [Proof: By Theorem 4.4.3 we have $sum ( eta + 1 + b sup \(mi )( eta + 1 + b sup \(pl ) <= 0$ where the sum is over the eigenvalues of the local graph distinct from the valency. On the other hand, $sum 1 = k$, $sum eta = 0$, $sum eta sup 2 = k lam$, where this time the sum is over all eigenvalues of the local graph.] ADDITION. .br .B 13.8 A triple cover of the strongly regular Suzuki graph .LP .SC Soicher .[[ Soicher 1993 three distance-regular .]] discovered the existence of a distance-transitive graph with automorphism group $3 . roman "Suz" :2$ and point stabilizer $G sub 2 (4) :2$ and diagram .KS [diagram] .KE In this case the $r$-covers of the underlying strongly regular graph (with parameters $(v,k, lam , mu ) = (1782,416,100,96)$) are feasible for $r mo "{"2,3,4,6,8,12,16,24,32"}"$. However, the $mu$-graphs in this strongly regular graph are edge-regular with $(v,k, lam ) = (96,20,12)$, and one easily sees that their components must have size at least 28. Since the above-mentioned 3-cover exists, it follows that these $mu$-graphs all have three components, each of size 32. Thus, this graph has no other distance-regular covers. [And in fact, the $mu$-graphs are $3(2. 1o2 2 sup 5 )$: three copies of the 2-coclique extension of the halved 5-cube.]