MUSEUM <">F COMPARATIVE ZOOLOGY. 277 



In short, while not denying that there maybe a slight average difference 

 between eastern and western specimens, as I know there is between those 

 of the Central Plains and those of the Atlantic States, I cannot allow that 

 it is at all sufficient to substantiate a specific difference. On the contrary, 

 I am confident that the above-named supposed species of the Pacific 

 States are based chiefly on individual variation perfectly parallel with 

 that seen in a large series of specimens from the Atlantic. States. No 

 one, in fact, seems to have felt very confident that any of them were 

 distinct from the eastern P. savanna. Dr. Coues has even repeatedly 

 expressed his belief that Passeixulus alaudinus is not permanently dis- 

 tinct from that species. " In a large series of the latter," he says, '• shot 

 about Washington, I have found fully as great differences as I have ever 

 detected in comparing the eastern with the western forms." * 



Dr. Cooper also refers as follows to the close resemblance of the P. 

 alaudinus to the P. sayulwichensis. He says, " I think it very doubt- 

 ful whether these specimens (which measure larger than the dimensions 

 given by Baird, though otherwise agreeing) are anything more than a 

 southern form of P. sandwichensis, though collected near San Diego. 

 .... Baird considers it almost identical with P. sacanna of the east, 

 and says that P. sand/vichensis differs from that species in its larger 

 size. Spring specimens have the superciliary stripe more decidedly yel- 

 low, so that there only remains a more slender bill to distinguish this 

 from P. savanna, and the larger size (characteristic of northern speci- 

 mens generally), with darker hues, from P. sandwichensis." f Respecting 

 P. anthinus Dr. Cooper remarks, " This species appears better marked, as 

 compared with P. savanna, than the preceding [P. alaudinus and P. sand- 

 wichensis], although I am not entirely satisfied that it is different." J 



The following measurements of twenty-six specimens (fourteen males 

 and twelve females), all taken at Ipswich during June and July, 1868, and 

 measured before skinning, indicates the range of individual variation pre- 

 sented by this species. The extremes are as follows : Length, 5.20 and 

 6.00, both males; alar extent, 7.61 and 9.75, both females; wing, 2.44 and 

 2.95 ; tail, 1 .64 and 2.25 ; tarsus, .75 and .88. The average dimensions are : 

 Length, 5.20 ; alar extent, 8.79 ; wing, 2.70; tail, 1.96 ; tarsus, .84. The 

 following are the extremes of the series of measurements of the western 

 Passerculi, given in Birds of North America : Length, 5.00 (P. alaudinus 

 Tamaulipas, Mex.) and 6.12 (P. sandicichensis, Fort Steilacoom, \V. T.) ; 

 alar extent, 8.50 and 9.37 (same specimens) ; wing, 2.50 and 2.95 (same 

 specimens) ; tail, 2.00 and 2.57 (same specimens). It thus appears that 



* Ibis, July, 1866, p. 289. 



t Ornithology of California, Vol. I, p. 182. 



J Ibid., p. 183. 



