314 ■ PEOF. b'ABCY W. THOMPSON ON THE [^PI*. 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 the openiug of the auditory meatus, 

 from which it is separated by a wide interspace. 



The infeinor lateral hand (c), or, again to use Pycraft's nomen- 

 clature, the ramal area (text-fig. 77, ram.tr.), starts from the apex 

 of the lateral angle of the horny lower mandible aud curves back- 

 wards 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-men- 

 tioned band, the median ventral or interramal tract starts as a 

 narrow triangle between the 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 Gollocalia (as a type of the Swifts) and Gapri- 

 mulgus ; but bearing in mind the general scantiness of our know- 

 ledge, 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 Gollocalia (text-fig. 79) the top of the head is feathered with- 

 out 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 into 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, friuging 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 



