_Parasites._--Wharton (1946:174) and Wharton and Hardcastle (1946:292, 296, 306) list the following species of chiggers (Acarina) from the Common Noddy from Guam and Ulithi: _Neoschöngastia bougainvillensis_, _N. americana solomonis_, _N. egretta_, _Acariscus pluvius_, and _A. anous_. Uchida (1918:484, 488) found the bird louse (Mallophaga), _Nirmus separatus_, on terms at Palau and at Ponapé he found _Colpocephalum milleri_ on the bird. Bequaert (_in litt._) has identified a fly (Hippoboscidae) as _Olfersia aenescens_ from a tern from Rota. _Remarks._--Of the Common Noddy Tern of the Pacific area, three subspecies are recognized by Peters (1934:346-347). _Anoüs stolidus ridgwayi_ is known from islands off the western coast of Mexico and Central America; _A. s. galapagensis_ is recorded from the Galapagos Archipelago; and _A. s. pileatus_ is found on tropical islands throughout the Pacific and west to Madagascar and the African coast in the Indian Ocean. These subspecies differ from one another principally in color, as noted by Ridgway (1919:545); _A. s. galapagensis_ is the darkest form, _A. s. ridgwayi_ is less blackish and more brownish in color of body, and _A. s. pileatus_ is between the two in coloring. _A. s. pileatus_ averages larger in length of wing and tail, but these measurements do not appear to be significant from a taxonomic standpoint. As shown in table 21, measurements of length of wing for specimens from throughout most of the Pacific area are almost the same. Length of tail is correspondingly uniform. There is a gradual increase in size of birds in the Tuamotus and Societies and east to Easter Island. In this region the average measurement for length of wing is 293 millimeters. The lengths of wing and tails are shorter in specimens from the Kermadecs and Norfolk Island, which may indicate relationships with the smaller birds of the Australian area, Western Melanesia and possibly Malaysia and the Riu Kiu Islands. I am unable to determine the subspecific status of the birds from the Kermadecs and Norfolk Island, because of the lack of sufficient material from the Australian region and Malaysia. Possibly Mathews' name, _A. s. gilberti_, is valid for the noddys of Australia and also for the birds at Norfolk and the Kermadecs. The small-sized birds of the Riu Kiu Islands have been designated as _A. s. pullus_ by Bangs. When specimens from the type locality of _A. s. pileatus_ in the Philippine Islands are available, the true relationships of the populations from Micronesia and the other areas in the Pacific can be ascertained.