MUSEUM OF COMPARATIVE ZOOLOGY. 275 



accompanying series of measurements shows that specimens occur in 

 Massachusetts as large and as small as any specimens of the genus of 

 which measurements are given by Professor Baird. 



In respect to the geographical distribution of these different supposed 

 species, it will be observed that of the three West Coast species, the larger, 

 P. sandwichensis, is northern, and the others, P. alaudinus and P. anthi- 

 nus, southern, which perfectly explains the difference in size that occurs 

 between them.* In respect to P. alaudinus and P. anthinus, one is only 

 the paler colored and the other the brighter colored form of the common 

 savanna sparrow as represented in the Pacific States ; the three supposed 

 species together forming a series similar to what is seen when a large 

 number of specimens of this bird from the Atlantic States are compared. 

 In other words, the characters whereon these species are based are evi- 

 dently only individual differences. The P. alaudinus is the form with 

 narrow streaks and generally paler tints, or that having a minimum inten- 

 sity of color ; the P. anthinus is that with the brighter tints, or with the 

 maximum intensity of color, the greater breadth of the streaks, and the 

 rufous suffusion below correlating with the generally brighter tints. Aside 

 from this normal range of variation referred to at length in Part III 

 as obtaining in all species, there i« that of season to be taken into 

 account, as the fading of the superciliary stripe and the grayer aspect of 

 the plumage above towards the end of the breeding season, through the 

 natural wearing and bleaching of the plumage, f and also the rufous suf- 

 fusion and greater amount of color characteristic of the renewed plumage 

 in fall. It will be noticed that authors report the occurrence of all the 

 western species either actually at or near the -same points^ while P. 

 savanna was not until recently supposed to occur on the Pacific slope of the 

 continent. § But one of the others have been announced from the plains 

 as far east as Nebraska, || and from Brownsville, Texas.^f 



In respect to the habits of these supposed species, there is nothing 

 attributed to the western one that is not equally applicable to the eastern 

 bird. Dr. Coues, it is true, says that in Southern California P. anthinus 

 seemed confined to the moist salt grass and sedgy weeds of the sea-shore 



* Since the above was written, Mr. Dall has given, not only P. savanna and P. sand- 

 mchensis, but also P. alaudinus and P. anthinus in his list of the birds of Alaska. (See 

 Trans. Chicago Acad. Sciences, Vol. I, pp. 283, '284.) 



t See Part III, p. 193. 



J See Professor Baird, " Birds of North America," Dr. Coues, " Notes on the Birds of 

 Arizona Territory," and Cooper's Ornithology of California. 



§ It has recently been reported by Mr. Dall as common in Alaska. 



|| P. alaudinus, Sclater's Catalogue of American Birds, p. 112. 



^ P. alaudinus, Baird, in Birds of North America, p. 446. 



