Measurements, as shown in table 20, indicate a wide range of sizes but, in most series, the averages are nearly the same. Nevertheless, it is evident that birds from the coast of China, the Riu Kius, Formosa, and the Philippines have a distinctly shorter wing than birds from the Moluccas, Melanesia, eastern Australia, Polynesia, and Micronesia. Further evidence of this is presented by Kuroda (1925:186) who lists the measurements of the wing of eight Crested Terns from the Riu Kiu Islands as 322 to 340 (average 330). The occurrence of populations with shorter wings has already been pointed out in the work of Oberholser (1915:520-526), who divided the short-winged birds into two subspecies. It seems advisable to recognize but one subspecies, _T. b. cristatus_, for the birds with short wings and another subspecies, _T. b. pelecanoides_, to include the birds with the longer wings (see figure 11). The average measurements of the length of wings of these two subspecies, 332, and 344, differ significantly, although there is some overlap in measurements. A few specimens at hand from the western part of Malaysia are in poor condition and not measurable. [Illustration: FIG. 11. Geographic distribution of _Thalasseus bergii_. (1) _T. b. bergii_; (2) _T. b. thalassinnus_; (3) _T. b. velox_; (4) _T. b. cristatus_; (5) _T. b. gwendolenae_; (6) _T. b. pelecanoides_.] Most specimens of _T. b. cristatus_ and _T. b. pelecanoides_ have lighter-colored upper parts than specimens of _T. b. velox_, but not so light-colored as specimens of _T. b. gwendolenae_. Size probably is a better character than color to use in separating these groups. In Micronesia, the NAMRU2 party observed Crested Terns at Ulithi, Peleliu and Truk, in August, September, and December, 1945, respectively. Birds were seen as singles or in small groups flying over the reefs. The birds were wary and difficult to approach, but they were conspicuous and easily identified. =Procelsterna cerulea saxatilis= W. K. Fisher Blue-gray Tern _Procelsterna saxatilis_ W. K. Fisher, Proc. U. S. Nat. Mus., 26, 1903, p. 559. (Type locality, Necker Island, Hawaiian Islands.) _Procelsterna cerulea saxatilis_ Yamashina, Tori, 10, 1940, p. 678 (Bikar); Hand-list Japanese Birds, 3d ed., 1942, p. 219 (Bikar); Mayr, Birds Southwest Pacific, 1945, p. 27 (Micronesia). _Geographic range._--Known from Marcus Island and the western Hawaiian Islands. In Micronesia: Marshall Islands--Bikar. _Remarks._--Yamashina (1940:678) recorded the taking of eight of these terns (5 adult males, 3 adult females) on July 10, 1932, at Bikar in the Marshall Islands. He gives the following measurements: wing, 180.5-188; tail, 104-113.5; exposed culmen, 24-26.5. This is the only known record for the species in Micronesia. =Anous stolidus pileatus= (Scopoli) Common Noddy