ON THE GENUS LATHAMUS. 65 



diffusely over the sides of the pelvis, and external to the last-named 

 tract, is the " lumbar feathering," which passes posteriorly on each side 

 into the narrower but more distinct " femoral tracts." These are con- 

 tinued onto the legs as far as the tarsi as the " crural tracts," clothing the 

 legs in a trouser-like way. On the inferior surface, on each side, is a 

 continuous tract, running from the upper part of the neck (where it may 

 or may not unite with its fellow of the opposite side), over the breast 

 and abdomen, to the anus. This " inferior tract," besides one or two 

 small branches running towards the humerus and patagium (the first 

 and second " humeral tracts "), gives off, at about the commencement of 

 the sternum, a more or less separate and well-marked external branch, 

 the " outer pectoral " tract, which runs down more or less parallel to the 

 main part of the inferior tract for a little way, but ceases before the 

 thighs. 



Amongst the various species of Psittaci I have examined, well marked 

 differences in some of these tracts occur, more particularly in the ar- 

 rangement of the " dorso-lumbar fork," and the greater or lesser develop- 

 ment of a distinct " outer pectoral " branch to the inferior tract. 



In Lathamus discolor (PI. I. figs. 1, 2) the inferior tract of each 

 side starts from about the angle of the jaw, and does not unite with its 

 fellow. On the sternum it is about eight or nine feathers broad at the 

 widest part, the feathering being rather strong and not close. As in P. Z. S. 1879, 

 most Parrots, there are two humeral tracts. The space on the carina P* " 

 sterui between the inferior tracts of the two sides is not wide. There 

 is a well-marked outer pectoral tract, about 1 inch long, distinguished 

 by its rather stronger and closer feathering. It is quite separate from 

 the main part of the inferior tract, the space between the two tracts 

 being about as broad as the latter tract itself. The outer pectoral has 

 the appearance of being somewhat dilated at its free end, owing to the 

 presence of a few irregularly placed and small feathers lying to the outside 

 of its termination. The main part of the inferior tract is rather narrow, 

 with its rows of four and five feathers each separated by rather consider- 

 able spaces. 



The scapular fork is rather long, the tracts being narrow and moderately 

 strongly feathered. 



The dorso-lumbar fork is elongated ; each arm is of nearly the same 

 length and breadth throughout, beginning a little outside the scapular 

 fork, with the part inside the arms of the latter represented only (as 

 usual in the Psittaci) by one or two rows of small feathers, placed singly 

 or in pairs. Each arm is composed of about fourteen rows of feathers 

 (counting to the junction with its fellow), the rows being four feathers 

 wide, rather close together, and of about the same width as the space 

 between the tracts. There is some tendency in some of the anterior 

 rows towards a dilatation of the tract, one or two of the rows being five . 



