130 abstracts: ornithology 



at Ophir will iJiove to be of high grade, owing to the complete removal 

 of limestone, but of small dimensions and confined to the immediate 

 vicinity of fractures and open bedding planes. Such small bodies are 

 not Hkely to lead to larger bodies of massive ore, unless they lie near 

 to groundwater level, or to some impervious stratum or fault that 

 impounded the waters containing the oxidized compounds of zinc. 



Where mixed sulphide deposits in limestone contain both copper and 

 zinc in considerable quantity the resulting carbonate ores of both 

 metals are to be expected in the oxidized zone, the copper carbonate 

 immediately below the position of the original sulphide body or its 

 siliceous casing, and the zinc carbonate below the copper carbonate. 



R. W. Stone. 



ORNITHOLOGY.— A^o^es on North American birds, IT. Harry C. 

 Oberholser. The Auk 34: 321-329. July, 1917. 

 The Arizona subspecies of T7reo bellii, originally characterized by 

 Mr. Ridgwaj^ and commonly regarded as inseparable from Vireo bellii 

 pusillus, is shown to be different and is recognized as Vireo bellii ari- 

 zonae Ridgway. The form of Baeolophus inoryiatus inhabiting the 

 Pacific Coast region from northern Lower California, north through 

 southern California to Santa Barbara County, and described by Mr. 

 Ridgway as Baeolophus inornatus murinus, is also reinstated. Two 

 race^ of Baeolophus wollweberi are admitted: Baeolophus wollweberi 

 wollweberi (Bonaparte), from central and southern Mexico, and 7?aeo/o- 

 phus wollweberi annexus (Cassin), from northwestern Mexico and the 

 contiguous portion of the southwestern United States. Reasons are 

 given for the recognition of Geothlijpis trichas brachidactyla (Swainson), 

 from the northeastern United States and southeastern Canada; Vermi- 

 vora celata orestera Oberholser, from the western United States, south- 

 western Canada, central and northern Mexico; Molothrus ater artemisiae 

 Grinnell, from the western United States and western Canada; and 

 Loxia curvirostra bendirei Ridgway, from the mountains of the western 

 United States; all of which have been discredited by recent authors. 

 The recent attempted elimination of Dendroica caerulescens cairnsi 

 on the ground of untenability is shown to be wrong, and its characters 

 as a recognizable race are given. The British form of Passer domesti- 

 cus, with which the introduced English sparrows of the United States 

 are found to be identical, recently described as Passer hostilis, is shown 

 to be but a subspecies of the continental European bird, and should 

 therefore be called Passer domesticus hostilis. H. C. 0. 



