322 PKOF, d'aECY W. THOMPSOIf ON THE lAW- ~} 



The dorsal area descends in a triangular patch far on to the sides 

 of the body midway between wing and leg ; it covers the head of 

 the femur and descends some little way behind that bone; it 

 terminates posteriorly in a pointed extension on the base of the 

 oil-gland, and a little way to the side of the latter it sends a little 

 triangular patch some short way downwards behind the femur. 



On either side of the breast-bone we have the broad median 

 ventral apterion, which extends all the way from the anus to the 

 region of the gape. 



The lateral cervical feathers-tracts, on arriving at the level of 

 the shoulders, communicate with the prepatagial marginal feathers 

 of the wing and then pass on into the broad ventral or pectoral 

 tracts. Between the prepatagial extension and the main pectoral 

 tract there is a well-marked patch running backwards towards the 

 hypopteron ; this last is the " pteryla lateralis " of Nitzsch. 



The ventral feather-tracts are broad along the sides of the 

 breast ; posteriorly they are continued by a single line of feathers 

 to join with a feather-tract behind the anus ; anteriorly over the 

 shoulder-joint they merge with the humeral tract and with the 

 marginal or pre-patagial wing-coverts, and each then runs forward 

 on the side of the neck, to be joined by the strip already mentioned 

 from the dorsal tract, and so to form the lateral cervical areas. 



We thus recognize the following apteria in Patagona : — 



(1) An elongated apterion on the top of the head divisible into 



an anterior and posterior portion. 



(2) A more or less crescentic supraocular apterion on each side 



of the top of the head. 

 (3 & 4) The apteria around eye and ear. 



(5) A small apterion extending backwards from the angle of 



the mouth, very narrow when the mouth is closed, but 

 stretching into a wide triangle when the mouth is open. 

 It is possible that this is directly continuous with a little 

 triangular apterion intercalated in the lateral feathering 

 of the neck just below and behind the ear. 



(6) The great posterior cervical apterion. 



(7) The dorsal apterion. 



(8) The lateral thoracic apteria, more or less subdivided by 



the downward extensions of the dorsal tract and also 

 encroached on by certain feathers, to be subsequently 

 described, in connection with the wing. This apterion is 

 continuous with a large naked space on the underside of 

 the wing, and with the bare space on the side of the femur. 



(9) The great ventral apterion which runs all the way from the 



fore part of the neck to the anus. 



(10) A triangular apterion, which we may call the scapular 



apterion, on each side of the neck, separated from the 

 posterior cervical apterion by the narrow anterior prolon- 

 gations of the dorsal tract, and separated by the humeral 

 tract from 



(11) the apterion on the dorsal surface of the wing. 



