Mar., 1912 A WEEK AFIELD IN SOUTHERN ARIZONA 63 walked along under some tall cottonwoods we flushed a flock of Turkey Buzzards (Cathartes aura septentrionalis) which mad4 them their roosting place. There were close to a hundred of them, and the air was black with their broad wings as they swung round and round over the tops of the trees. We reached the machine just at dusk and after a hasty supper, loaded our baggage and started on the last ten miles of our trip, arriving in Tombstone at nine o'clock. Our speedometer registered three hundred and seventy-five miles for the trip. While not up to my expectations as a collecting trip, it had been successful enough to be satisfactory, with variety enough to make it thoroughly enjoyable. PASSERELLA STEPHENSI IN MARIN COUNTY, CALIFORNIA . By JOSEPH MAILLIARD .WITH THREE PHOTOS NTIL recently there has been no sufficiently large series of Passerella got- ten together in California to permit of intelligent comparison of the var- ious individuals a collector might obtain. This lack of material for com- parison has left him in the dark as to subs. pecific determinations. But now, under the care of the Museum of Vertebrate Zoology, University of Cali- fornia, at Berkeley, there is a fine working series consisting of specimens belong- ing to the museum itself, and to the Grinnell, Swarth and Morcom collections. These contain specimens of Passerella taken in many places on the Pacific Coast, from Southern California to as far-north as Kotzebue Sound, Alaska, many of them--notably the northern forms and P. stephensi?having been taken on their breeding; grounds either actually during the breeding season or before the young were old enough to migrate. Realizing this to be our opportunity, it seemed time for us to undertake the difficult task of identifying the various individuals of this group in our own col- lection (collection of J. & J. W. Mailliard, San Francisco), the majority of which were migrants or winter residents. Mr. Joseph Grinnell of the Museum of Ver- tebrate Zoology gave us most generous assistance in this work, and as'he had personally collected many breeding specimens his assistance was especially valu- able. It happens that in very cold winters on the Rancho San Geronimo, Marin County, California, we have sometimes 'found, in a sort of rocky mesa covered with dwarfed cypress, ceanothus and low, scrubby manzanita bushes, on the top of the range, a form of Passerella that differed from the commonly found winter forms in having a very heavy bill and being of a much lighter and more grayish' coloration. C.A. Allen of San Geronimo (,postoffice formerly known as Nicasio) took quite a few of these in times past and sold them to eastern collectors as P. i. megarhyncha--Thick-billed Sparrow--and as far as we know they have always been so accepted. In fact this form is mentioned by the writer in "Land Birds of Marin County, Cal." (ConDOR, n, May, 1900, p. 62), under megarhyncha
as "casual visitant," with no comment since, and is now in the Third Edition of
the A. O. U. Check-List of North American Birds as such. There should be
