lo THE SCOTTISH NATURALIST 



coverts, and a few new feathers appearing on the underside ; 

 the fourth primary was partly in quill in both wings, longer 

 in the left than in the right, and the secondaries were fresh ; 

 the centre pair of tail feathers were almost wholly in quill. 



A Black Tern {Hydrochelidon nigra nigra) from the Gold 

 Coast, an immature bird without a date, had a few feathers 

 coming in on the back, some being black, others grey; the 

 bastard and second primaries and one secondary were partly 

 in quill, and there were three fresh feathers in the tail partly 

 in quill, the rest being old and worn. Four adult and one 

 immature White-winged Black Terns {Hydrochelido7i leucop- 

 tcra) were examined, all from Uganda. The immature bird 

 was taken on 19th September 1906, and had some feathers in 

 quill on the back; the adults, two of which were assuming 

 summer and two winter plumage, were more interesting. A 

 male, procured on 5th April 191 1, was in heavy moult all over 

 the head and body ; another, assuming summer plumage, but 

 without a date, showed heavy moult all over the body ; the 

 tail was chiefly fresh, but one old grey feather remained and 

 one of the new white ones was only half grown ; the sixth 

 primary in each wing was still partly in quill, and the 

 tertiaries and scapulars were in heavy moult : evidently this 

 species indulges in a complete spring moult. A male got on 

 8th September 1906 was assuming winter dress, and had the 

 second primary in each wing only half grown and a tail 

 feather still in quill ; the other (no date) had a little moult 

 on back of head, back, breast, and some tail coverts : this 

 bird too was assuming winter plumage. Three Gull-billed 

 Terns {Sterna nilotica niloticd) from Uganda all showed signs 

 of moult. A male got on 28th November 1910 had the first 

 (bastard), second, and third primaries in both wings partly in 

 quill, new tertiaries were coming in, and one tail feather was 

 partly in quill. A female obtained the same day had the 

 first and second primaries very old and worn ; the new second 

 coming in was quite short and in quill; some secondaries 

 and a tertiary were coming in fresh on each side, the left 

 outer tail feather was partly in quill, while the corresponding 

 one on the right side was full grown. The other bird, which 

 was not quite adult, unfortunately had no date; it showed a lot 



