130 University of California Publications in Zoology [Vol. 21 



undesirable to take any such formal action, and I prefer merely to 

 indicate what may be the explanation of the two different types of 

 birds I have here included under the subspecific name unalaschcensis. 

 Birds of the Alaska Peninsula type show a range of variation 

 undoubtedly indicative of intergradation with simwsa, the subspecies 

 next adjoining on the southeast. There are also some individuals 

 apparently inclining toward insularis, of the closely adjacent Kadiak 

 Island. This range of variation, including apparent intergrades 

 as above indicated, as well as the two diverse types of iinalaschce7isis, 

 all occurring among winter birds in California, has added greatly to 

 the difficulty of recognizing the relationships of many specimens there 

 taken. At the outset of this study the proper separation of unalasch- 

 censis and insularis from the confused series brought together, was 

 one of the most difficult problems encountered, and while the present 

 solution of the question seems logical and fairly satisfactory, it must 

 be borne in mind that it is largely hypothetical, and advanced merely 

 as an apparent explanation of the observed facts. Absolute proof of 

 its correctness awaits the study of additional sunmier specimens. 



In the range of variation seen in winter birds, all the Alaska 

 Peninsula type show some trace of brown or rufous. Even the summer 

 birds show it to some degree, especially in the breast spotting. The 

 plumbeous colored type of bird is much less rufous, many of this 

 type presenting a dull slaty effect with scarcely a trace of reddish 

 anywhere. 



In its southward migration unalaschcensis, like sinuosa, apparently 

 avoids the coast to a great extent. This is especially noticeable in 

 California, where nearly all the record stations are at inland points 

 until southern California is reached (see map, fig. 0). Specimens 

 taken at Helena, Trinity County, February 17, at Drytown, Amador 

 County, December 8 and February 29, at Lakeport, Lake County, 

 December 13, and at Berkeley, February 15, are apparently indicative 

 of winter visitants at these points, but they are only scattered indi- 

 viduals, the main winter home of the subspecies apparently lying south 

 of Tehachapi in southern California. 



In the accompanying list of specimens (pp. 186-187) birds of the 

 plumbeous colored type are marked with a superimposed figure (^) 

 above the collection number, and it will be seen that this type of bird 

 in winter is practically restricted to southern California. The paler 

 colored Alaska Peninsula bird, found in southern California too, 



