diff --git a/README.md b/README.md
index 959d5a6c..aed9d58c 100644
--- a/README.md
+++ b/README.md
@@ -13,6 +13,8 @@ structures comprise:
 - `Heap`, an imperative heap based on `SplayTree`
 - `Graph`, a polymorphic imperative directed graph (on top of `PHashtbl`)
 - `Hashset`, a polymorphic imperative set on top of `PHashtbl`
+- `LazyGraph`, a lazy graph structure on arbitrary (hashable+eq) types, with
+basic graph functions that work even on infinite graphs, and printing to DOT.
 - `FQueue`, a purely functional queue structure
 - `Heap`, a purely functional polymorphic heap
 
@@ -20,7 +22,11 @@ Other structures are:
 
 - `Univ`, a universal type encoding with affectation
 - `Cache`, a low level memoization cache for unary and binary functions
+- `PersistentHashtbl`, a semi-persistent hashtable (similar to
+[persistent arrays](https://www.lri.fr/~filliatr/ftp/ocaml/ds/parray.ml.html))
 - `Deque`, an imperative double ended FIFO (double-linked list)
+- `Future`, a set of tools for preemptive threading, including a thread pool,
+monadic futures, and MVars (concurrent boxes)
 - `Vector`, a growable array (pure OCaml, no C; not tested)
 - `FlatHashtbl`, a (deprecated) open addressing hashtable with
     a functorial interface (replaced by PHashtbl)
diff --git a/tests/benchs.ml b/tests/benchs.ml
index 115f15e7..c43a1fec 100644
--- a/tests/benchs.ml
+++ b/tests/benchs.ml
@@ -217,6 +217,12 @@ let skiplist_find l =
       ignore (SkipList.find l i);
     done
 
+let array_find a =
+  fun n ->
+    for i = 0 to n-1 do
+      ignore (Array.get a i);
+    done
+
 let _ =
   List.iter
     (fun len ->
@@ -227,6 +233,7 @@ let _ =
       let h'''' = ifhashtbl_add len in
       let h''''' = ipersistenthashtbl_add len in
       let l = skiplist_add len in
+      let a = Array.init len (fun i -> string_of_int i) in
       Format.printf "----------------------------------------@.";
       Format.printf "try on size %d@.@.@." len;
       Bench.bench [
@@ -237,8 +244,9 @@ let _ =
         "ifhashtbl_find", (fun () -> ifhashtbl_find h'''' len);
         "ipersistenthashtbl_find", (fun () -> ipersistenthashtbl_find h''''' len);
         "skiplist_find", (fun () -> skiplist_find l len);
+        "array_find", (fun () -> array_find a len);
       ])
-    [10;20;100;1000;10000;100000]
+    [10;20;100;1000;10000]
 
 (** {2 Sequence/Gen} *)