1879.] MR. W. A. FORBES ON THE GENUS LATHAMUS. 169 



the widest part, the feathering being rather strong and not close. As 

 in most Parrots, there are two humeral tracts. The space on the carina 

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

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

 tinguished 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 tiie outside of its termination. The main 

 part of the inferior tract is rather narrow, with its rows of four aud 

 five feathers each separated by rather considerable 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 strength and breadth throughout, beginning a little outside 

 the scapular fork, with the part inside the arms of the latter re- 

 presented 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 feathers wide. In the more 

 anterior parts of each arm, the most internal feather of each 

 row is often placed in front of and at an angle with the other 

 feathers composing it, and so comes to stand between two rows of 

 three feathers each ; so that at first each tract looks as if made up 

 of rows of three (or four) feathers alternating with single feathers. 

 This tendency to a 3.1.3 arrangement, however, disappears in the 

 the more posterior parts of the tracts, the four feathers of each row 

 there standing in a direct line with one another. The two arms 

 unite to form the "handle" at about three quarters their entire length ; 

 after the junction the tract narrows rather rapidly towards the tail. 

 The dorso-lumbar fork is throughout quite distinct from the lumbar 

 feathering, which is very weak and difi^use. 



In all the truly Platycercine' forms that I have examined— namely 

 Platycercus eximius and pennantii, Psephotus hcematogaster (four 

 specimens) and P. heematonotus, Pyrrhulopsis splendens and P.perso- 

 nata, Cyanorhamphus auricepsand C. nuvce-zeatanclice — the disposition 

 of the outer pectoral tract and dorso-lumbar fork resembles essen- 

 tially that of Lathamus. In all the outer pectoral is a distinct, more 

 closely feathered, and rather narrowish tract, clearly separated 

 throughout from the main part. In Cyanorhamphus this tract is 

 distinctly hook-like, dilated at the end. In all the same length^, and 

 uniformity in strength and width, of the arms of the dorso-lumbar 



* I. e. excluding Aprosmictus, Polyteles, Ewphema, Peeoporus, &c. 



^ In Pe. pennantii, and in the two species of Pyrrhulo2)sis I counted fourteen, 

 in C. auriceps thirteen, in Ps. hcBmatonotus tliirteen, aud in Ps. //(Binafogaster 

 eleven rows of feathers in the arms of this tract to their junction. 



