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Show 314 PROP, D'ARCY W . T H O M T S O N O N T H E [Apr. 2, of the neck; secondly, a little patch extending to the inner canthus of the eye, there becoming connected with a ring of tiny feathers that closely surrounds the eye very near the margin of the eyelid to the number of about 16 or 17 above and below, and finally continued backwards from the posterior canthus; thirdly, a well-defined band which forms firstly a well-defined row of feathers running backwards below the eye, secondly a band running downwards in front of the ear, and thirdly, between these two, a circlet of feathers surrounding tbe opening of the auditory meatus, from which it is separated by a wide interspace. The inferior lateral band (c), or, again to use Pycraft's nomenclature, the ramal area (text-fig. 77, ram.tr.), starts from the apex of the lateral angle of the horny lower mandible and curves backwards and downwards until below and a little in front of the ear it becomes confluent with the adjacent tracts, and merges in the general feathering of the sides of the neck. Separated in front by a considerable space from the last-mentioned band, the median ventral or interramal tract starts as a narrow7 triangle between tbe rami of the lower mandible, and very-soon, about the level of the front of the eye, forks into two lateral branches which proceed downwards, merging with the lateral cervical tracts (text-fig. 77). The arrangement of feathers on the head in Patagona is in striking contrast with the more uniform arrangement of ordinary Passerines. For purposes of comparison, I have examined a few birds only, especially Collocalia (as a type of the Swifts) and Caprimulgus ; but bearing in mind the general scantiness of our knowledge, and also what we already know of the variability of the pterylosis within even limited groups, it is plain that we need countless additional observations before the comparative method shall be properly available. In Collocalia (text-fig. 79) the top of the head is feathered without any median interruption from the beak to the nape of the neck, the feathers in front reaching to the border of the gape external to the nostrils. Laterally, a distinct crescentic apterion separates this feathered area, whose outer feathers are larger than those within, from a single row of outwardly directed feathers running above the eye and again separated from it by a considerable interspace. This row starts, very much as in the Humming-bird, from a loral patch which feathers the base of the bill between nostril and eye, and from which another row of feathers passes below the eye to stop short immediately behind it. Between these two rows is a row of eyelash-feathers on the lower lid only, continued iuto a little group behind the outer canthus. A third line of feathers starting from the same region becomes connected with the circlet of feathers around the wide auditory aperture. Below the gape, fringing its margin, a ' ramal' band of feathers is present separated by a narrow space from the broad feathered ' interramal' area which occupies the rest of the mandibular triangle. To a certain extent there is a resemblance traceable between this |