If we consider all the brown _Pipilos_ as modifications of one primitive species, it will be well to consider the Arizonan and New Mexican bird as the central figure around which the others are grouped. The common character will then be varied in the California race, _crissalis_, by the absence of decided rufous on crown, a darker shade of color, and an extension of the gray of sides over the whole under parts, almost entirely displacing the white. The wing is more rounded, and the general dimensions larger southward on the central plains of Mexico; the general tints are almost precisely as in the California bird, except that the white of belly is very evident; but the chestnut cap and extended whiteness of belly, together with the pointed wing of _mesoleucus_, are wanting. In _P. albigula_ of Cape St. Lucas we have the general characters of _mesoleucus_, with paler colors, more restricted spots encircling throat, and a tendency to white in its lower part. In this it approaches _albicollis_ of Southwestern Mexico. HABITS. This little-known form was first obtained by Dr. Kennerly, naturalist to the Pacific Railroad Expedition on the 35th parallel, under Lieutenant Whipple. He met with it at Bill Williams Fork, in Arizona, February 5, 1854. It was described by Professor Baird the following June. Dr. Kennerly furnished at the time no information in regard to its habits. Dr. Heermann, in his Report on the birds observed in Lieutenant Parke’s expedition, mentions having met with this species in the vicinity of Tucson. Its habits, so far as he could judge of them from his opportunities, appeared very similar to those of _Pipilo aberti_. Lieutenant Couch met with this species at Santa Catalina, Mexico, in April, 1853, but furnishes no information in reference to its manners. Mr. J. H. Clark, who obtained a specimen near the Copper Mines of the Mimbres, states that they were met with in abundance in the deep valleys or cañons of that region. They were almost always in or about the thick clumps of bushes, several usually being in company. Dr. Kennerly, who met with them on a second trip, in June, 1855, near Los Nogales, in Mexico, speaks of them as not very common in that region. He found them preferring the dense bushes in the valleys. When approached, they became very restless, flying from one bush to another, accompanying their motions with very peculiar notes, which he does not describe. Dr. Coues found this species abundantly distributed throughout the warmer portions of New Mexico and Arizona, from the valley of the Rio Grande to that of the Colorado. He did not observe any at Fort Whipple, though they were found breeding some twenty-five miles to the southward. He found them associating freely with _Pipilo aberti_, and inhabiting the same regions. The two birds have very similar habits.