498 PROCEEDINGS OF TEE NATIONAL MUSEUM. vol.47. 



Its coordinate on the right has attained two-thirds the length of the 

 lateral retrices. 



Cat. No. 181104, U.S.N.M.; male; Ai-u Bay, East Sumatra, Novem- 

 ber 18, 1905. In this bird seven of the lateral paired feathers are fully 

 developed with an eighth outermost just appearing on the right side, 

 while its mate on the left has evidently been fully developed for some 

 time. The fourth from without on the right is a bright clean feather 

 which has not quite attained its growth, a small portion at the base 

 being stiU inclosed in a sheath, while the corresponding feather on the 

 left is old, much worn, abraded at the tip, and dull in general color. 

 Of the central pair, the left feather is longer and is faded and much 

 worn, while the right rectrix, 6 inches less in length, is still growing 

 as is shown by the sheath-inclosed base. 



Cat. No. 159449, U.S.N.M.; female; Lay Song Hong, Trong, Lower 

 Siam, November 21, 1896. The four outer pairs of rectrices are 

 developed normally, while one alone of the central feathers is fully 

 grown and it is faded and somewhat abraded . At its base on the left 

 side is the other member of the median pair, a bright, new, developing 

 feather three-fourths as long as the outer rectrices. 



Cat. No. 181105, U.S.N.M.; male; Aru Bay, East Sumatra, January 

 1, 1906. The eight shorter feathers are intact and comparatively 

 new. The right member of the central pair is fuUy developed and in 

 fair condition as regards color and abrasion; while its companion on 

 the left is one-fourth the length of the lateral rectrices and has just 

 broken its sheath. 



Cat. No. 180966, U.S.N.M.; male; Tarussan Bay, West Sumatra, 

 January 9, 1905. The tail is well developed, the four outer pairs of 

 rectrices being entirely bright and new. One long feather on the right 

 side is comparatively new, showing few signs of wear. Its companion 

 on the left shows only in that the sheath projects one-half inch beyond 

 the skin of the pygal elevation and as yet shows no sign of breaking 

 to allow the vane to expand. 



Cat. No. 181699, U.S.N.M.; male; Balik Papan Bay, East Borneo, 

 February 9, 1909. This specimen has three of the outer feathers on 

 the left side fully developed, the second from the outside being one- 

 third as long as the others. On the right haK only two feathers are 

 fully developed; the first is just breaking its sheath and the second is 

 one-half as long as its fully grown companions. Of the median pair, 

 the left is longer while its parallel on the right is a trifle shorter and is 

 evidently older and in poorer condition, being worn at the tip nearly 

 to the shaft. 



Cat. No. 181249, U.S.N.M.; male; Sungei Makapan, East Sumatra, 

 February 18, 1907. The right member of the fourth pair barely shows 

 as a projecting quiU from the uropygium, while its companion on the 

 left is double its length and is just breaking the tegumentary sheath. 



