538 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM, 



in size and form of the bill iu rostratus, I am unable to find among 27 

 examples of the latter a single one having the bill nearly so slender as 

 in the type of guttatus, as the following measurements of the latter com- 

 pared with the minimum corresponding measurements of rosiratus will 

 show:] 



From the above figures it is evident that the difference between spec- 

 imens of P. rosiratus is greater than between smaller individuals of 

 the same and the so-called P. gnttatiis^ except in the tJiichiess of the hill. 

 In fact, all other measurements intergrade, as does also, unquestion- 

 ably, the coloratiou. It therefore follows that if P. guttatus is allowed 

 to rank as a species, or even subspecies, its claim to such rauk rests 

 solely upon the peculiarly slender bill. 



Two specimeus collected on the island of San Benito, Pacific coast of 

 Lower California, by Dr. T. H. Streets, U. S. ^. (i^os. 7063G and 70G37, 

 U. S. Nat. Mus.), are labeled in the handwriting of Dr. S. '^ Passerculus 

 sanctorinn Ooues (Type)," and are quite appreciably dilierent in colora- 

 tion, and alsoiu tbe form of the bill, from ordinary P. rostratus, includ- 

 ing an example (No. 70635) obtained by Dr. Streets at Todos Santos. 

 The coloration of these two specimens being (ssentially identical with that 

 of the type of P. guttatiis I had referred them to that supposed species ; 

 but I now find that so far as measurements go, they belong rather to 

 P. rosiratus. Certain it is, that among Mr. Belding'sLa Paz specimens 

 are some which I cannot in any way distinguish from these San Benito 

 specimeus, while others of the same series lead the way by the most 

 gradual but complete transition to " typical " rosiratus. In order to 

 make the matter more plain, I have divided the collection before me into 

 three series, as follows : {a) Specimens typical of rosiratus as to colora. 

 tion ; (b) types of '' P. sanctorum Cones ;" (c) specimens agreeing with 

 "P. sanctorum'''' in coloratiou ; [d) specimens agreeing with the type of 

 "P. guttatus'''' in coloration, and (e) the type of "P. guttatus'''' itself. 



