_Evolutionary history of Corvus kubaryi._--Meinertzhagen (1926:59) writes that "Environmental influences seem to be mainly, if not entirely, responsible for geographic differences in the genus _Corvus_." Such may be the case in _C. kubaryi_, which is a small, dull-colored crow with a relatively unmodified bill. In structure, it has little resemblance to other crows found in the Pacific area. Kittlitz was the first to note a resemblance between the bird at Guam and one in the Philippines. Oustalet (1896:70) wrote that the bird at Guam is related to crows of the Moluccas and New Guinea. Although not closely related to the Hawaiian Crow, _C. tropicus_, both have little gloss on their feathers, a character which is common to many of the insular populations of crows. Mayr (1943:46) is of the opinion that the Hawaiian bird was derived from a North American ancestor, although Bryan (1941:187) suggests that it is related to _C. macrorhynchus_ of southeastern Asia and remarks that the Hawaiian Crow, "has some relation to the Guam Crow." In looking for the ancestral stock of _C. kubaryi_, the several species of crows which occur to the north, west and south of the Marianas have been examined. In size and general structure, _C. kubaryi_ appears to be closest to the _C. enca_ group, and not as closely related to the _C. macrorhynchus_ group. The small size, the shape of the culmen, the lack of pointed feathers on the breast, and the presence of white on the basal parts of the feathers of the nape are characters which _C. kubaryi_ has in common with _C. enca_. Nasal bristles cover the frontal base of the culmen in _C. kubaryi_; this character is found also in _C. enca florensis_. _C. kubaryi_ differs from the _C. enca_ group by lacking the purple sheen on the upper parts; this sheen is conspicuous in the latter species. _C. kubaryi_ appears to have little in common with _C. meeki_ of the Solomons and _C. orru_ of the Moluccas and New Guinea area. There is apparently no close relation between the Marianas Crow and the crow which reaches the Bonins. The latter crow, according to the Hand-list of Japanese Birds (Hachisuka _et al._, 1932:1), is called _C. coronoides hondoensis_ Momiyama and is apparently now extinct in the Bonins. In summary, it may be said that _C. kubaryi_ is an isolated and modified species of crow, which probably has been living at Guam and Rota for a considerable length of time. Whether it once lived on other islands in Micronesia is unknown, but it is entirely possible that the present population may represent a remnant of one which formerly had a more extensive distribution. The characters which show its distinctness from possible ancestral species include its small size, its slender bill, and its dull coloration. It is thought to have been derived from the _C. enca_ group, _C. e. pusillus_ of the Philippines or _C. e. celebensis_ of the Celebean area. =Luscinia calliope calliope= (Pallas) Siberian Rubythroat