4 PEOCEEDIlSrGS OF THE NATIONAL MUSEUM vol.77 



material available of Colius indicu^ and Colius castanotus has been 

 very slight, but of Colius striatus (subspecies striatus^ hihmjuensis, 

 erlangeri^ hilgerti^ and jebelensis) , of Colius macrourus (races mac- 

 Tourus and fulclier) , and of Colius leucocephalus tumeric the mate- 

 I'ial has been abundantly ample to demonstrate beyond question the 

 centripetal sequence of their tail molt. 



Among the buccos and puff birds, the only species that I have 

 found in proper condition for this study are Bucco dysoni and 

 Bucco rufjcollis ruflcollis. The former appears to be irregular, the 

 latter centrifugal in the sequence of rectrix renewal. 



Only two forms of jacamars with molting tails have been exam- 

 ined: Golbula chalcothorax and Galhalcyrhynchus purusiaiius, both 

 of which have centrifugal molts. 



I have found no evidence of a centripetal type of tail molt in either 

 the kingfishers or the parrots, but the molting material has not been 

 extensive. Heinroth (12) reports only a centrifugal molt in the 

 Alcedinidae, and an irregular molt in the Psittacidae. 



The kakelaars (Phoeniculidae), of which three forms have been 

 studied {Phoeniculus purpureus niloficus, Phoeniculus somalicus 

 neglectus^ and 8coptelus aterrirtius notatus)^ suggest the condition 

 reported b}^ Stone in the woodpeckers. Their tail molt is centrifugal 

 beginning with the next to the middle pair and proceeding out- 

 ward, the middle pair being shed after the fourth pair (counting 

 from the middle). Scoptelus appears to be somewhat less definite 

 in this matter than Phoeniculus. 



Only one bee eater {M elittophagus revoilii) has been available in 

 sufficient quantity of molting specimens. Its tail molt is irregular 

 as far as I can make it out ; that is, the condition shown in one speci- 

 men contradicts that shown in another, while a third is different 

 from either of the first two. 



The hornbills are of great interest because of a sexual difference 

 in the tail molt. The females lose all their rectrices simultaneously, 

 while in the males the molt is a long drawn-out process. This ap- 

 pears to be correlated with their peculiar nesting habits. The 

 female is imprisoned in a hole in a tree, the entrance to which is 

 largely plastered over preventing the passage of the bird to and 

 from the nest. While confined in this small space all the old 

 rectrices (and the remiges too) are dropped and new ones are grown. 

 In the males, the tail molt is usually contrifugal, definitely and very 

 regularly so in Lophoceros nasutus nasutus and in Lophoceros ery- 

 throrhynchiis erythrorhynohus; less definite, somewhat irregular, but 

 on the whole, centrifugal in Lophoceros decheni^ Lophoceros jacksoni 

 Bycanistes cristatus cristatus and Bucorvus abyssinicus, where it 

 starts with the middle pair of rectrices and then becomes somewhat 



