The vultures of the New World show their distinctness from other diurnal birds of prey in a number of ways. Recently, their pterylosis has been compared with that of other falconiforms by Compton (Univ. Calif. Publ. Zool., vol. 42, 1938, pp. 173-212). He showed that the feather arrangement in the Falconiformes falls naturally into three types, known as the accipitrid, falconid, and cathartid patterns. Of the species which he dissected, the Turkey Vulture (Cathartes aura) and the Osprey (Pandion haliaetus) showed the cathartid arrangement. This led to the conclusion that the Osprey belongs to the suborder Cathartae. Manifestly it is desirable to determine how uniform the pterylosis may be among the New World vultures (family Cathartidae) and to test the applicability of Compton's definition of the cathartid type. The opportunity to study the feather tracts of the California Condor (Gymnogyps californianus) came about through the efforts of Mr. J. R. Pemberton and Mr. Perry Sprague. On January 1, 1937, Mr. Sprague came upon an adult condor that was gorged with food, unable to fly, and apparently sick. This was on the Tejon Ranch east of Bakersfield. The bird was taken to ranch headquarters and fed upon meat and squirrels, but it disgorged everything it ate and became weaker. Finally it died on January 10, the nature of its infirmity as yet undetermined. Mr. Pemberton learned of its death and took immediate steps to send the bird to the Museum of Vertebrate Zoology at Berkeley. Upon its arrival it was embalmed, thus assuring a chance to study the anatomy of this vanishing species. We are greatly indebted to Mr. Pemberton and Mr. Sprague for the essential parts they played in making this study possible and for the opportunities for further investigations that lie before us. To facilitate reference to Compton's work, we follow his nomenclature and plan of description. At the end of the discussion of each feather tract is a summarized comparison of Gymnogyps and Cathartes. Doubtful points relative to the pterylosis of Cathartes have been rechecked by examination of alcoholic specimens. Capital tract.-The head feathering, though much reduced, is unequally developed in different regions. There is a transverse band of small plumaceous feathers, 6-12 mm. long, that occupies the frontal, anterior superciliary, and loral regions. The frontal and rostral regions are well feathered from slightly in front of the nostril to the level of the posterior margin of the eye along the median line. Laterally, the feathered area is restricted and sparser, passing ventrally as a band between the eye and the nostril to merge with the loral region. In parts of the frontal region the feathers almost completely obscure the skin. The feathers of the rostrum are arranged in a whorl which centers between the anterior ends of the nostrils. The feathers of the loral region are directed posterodorsally in the upper section near the eye, but posteroventrally in the lower section. The loral region is connected at its ventral margin with another, triangular area beneath the eye. This latter is occupied by more reduced feathers, 4-5 mm. in length, intermediate between those of the loral region and the vestigial hair-like feathers of the other parts of the head. This area below the eye occupies part of the anterior auricular region and the upper margin of the malar area (see Compton, op. cit., fig. 1, p. 181). The posterior auricular region consists of a ring of fairly heavy bristles about the meatus, not directly connected with the anterior auricular area. The ring is well developed anteriorly and dorsally. The coronal region is bare except for two patches of weak bristles, about 2 mm. in length, on either side near its posterior boundary. These are separate from the occipital, postauricular and submalar regions. The similar, sparse bristles of these latter regions form a continuous zone that meets the anterior and posterior auricular regions. The interramal and ocular regions are entirely bare. Compared with Cathartes aura, the capital tract is less uniformly feathered. In both, the loral region is relatively well feathered, but no feathers are plumaceous in Cathartes. Gymnogyps lacks eyelashes and many other parts are entirely naked (fig. 65). In Cathartes only the normal apteria about the eye, the anterior interramal region and the rostrum are bare, and the vestigial feathers of other areas are less widely spaced.