554 abstracts: ornithology 



not supported by specimens are mentioned in notes. All the species 

 mentioned in Ward's Flora (the standard list of the region up to the 

 present) and its Supplements have been accounted for, even though 

 they cannot now be verified by specimens, some in synonymy and some 

 as being errors of identification. There are formally listed 646 genera 

 and 1630 species, and many more are mentioned in notes as being waifs. 

 There are two keys to families, one based mainly upon vegetative char- 

 acters, the other mainly upon floral characters. There are also keys 

 to genera and to the species. Under each species is mentioned the com- 

 mon name, the habitat, the distribution in the District, the flowering 

 period and the general distribution. An introduction gives a brief 

 history of botanical activity in the District and a short account of the 

 geologic and ecologic features of the region. The work concludes 

 with a Glossary and Index and is accompanied by 42 plates giving 57 

 halftones, some illustrating the ecologic features of the flora, others 

 several of the interesting species. A. S. H. 



ORNITHOLOGY. — Washington region. (February and March, 1918.) 

 Harry C. Oberholser. Bird Lore 20: 231-32. 1918. 



February and March are usually the least favorable months for bird 

 observations about Washington. In the year 191 7, however, these 

 months were notable for the many ducks which frequented the Potomac 

 River. Two species, Marila americana and Spatula clypeata, both 

 of which are rare about Washington, particularly in the spring, were 

 observed in March. Furthermore, Nettion carolinense and Aristonetta 

 valisineria remained later than ever before. Notwithstanding the 

 very severe winter a number of early migrants appeared considerably 

 ahead of their schedule; Fulica americana on March 9, earlier than any 

 previous record. Some species, such as Regulus satrapa, N annus 

 hiemalis hiemalis, and Sitta canadensis canadensis have been unusually 

 scarce; others, such as Passerella iliaca, at times more than commonly 

 numerous. H. C. O. 



ORNlTHOhOGY.— Notes on North American birds. VII. Harry 

 C. OberholsER. Auk 36: 81-85. January, 19 19. 

 An investigation of the American Nettion carolinense shows that this 

 bird is clearly a distinct species and not a subspecies of the European 

 Nettion crecca. On the other hand. Circus hudsonius (Linnaeus) proves 

 to intergrade individually with Circus cyaneus of Europe, and should, 

 therefore, stand as Circus cyaneus hudsonius (Linnaeus). The gray 



