822 LETTER FROM DR. G. HARTLAUB. [NoV. 14, 



the curious long quill-feather is a supernumerary one. It is inserted, 

 as Swainson very accurately remarks, immediately between the pri- 

 mary and secondary quills, and the naked basal or insertional part 

 of it is curiously curved. The apical webs of these feathers are 

 very broad, and show some broad black indistinct bands on a dark 

 blackish ground. 



" Now in Semiophorus vexillarius there is not even a trace of all 

 this. The long ornamental wing-feather is the regular ninth quill, 

 regularly webbed throughout, and getting m.ore and more narrow 

 towards the tip, where it becomes gradually very narrow ; the colour 

 of this feather is a pale brownish grey with whitish shafts on the 

 upperside, and of a uniform brown with the shaft brown on the 

 underside. The eighth quill-feather is double the length of the 

 seventh. 



"Semiophorus vexillarius is a much larger bird. I give some of 

 the relative dimensions : — 



5. vexillarius. M. longipennis. 



Long, rostr. a fr 0" 5'" 0" 3'" 



al£e 8i 6| 



caudge 4 9 34 



■ tarsus Oil o" 9 



" The colour of the wings is totally different in these birds, not less 

 so than their form. In M. longipennis all the quills are alternately 

 banded with black and rufous ; there is no white on the wing of this 

 species. But the contrary is the case in -S. vexillarius : in this species 

 the colour of the remiges is of a brilliant black ; the outer web of the 

 first has the great middle portion white ; the basal portion of all and 

 the apical margin of the smaller quills is pure white, as well as the 

 tips of the larger tectrices. 



"The middle of the abdomen, the vent, and the under tail-coverts 

 are pure white in S. vexillarius, while these parts are fulvous and 

 darkly fasciated in M. lonyipennis. 



" The ground-colour of the underside of the tail is whitish in S. 

 vexillarius, pale rufous in M. longipennis. 



" So much about S. vexillarius being the freshly moulted M. 

 longipennis. It is sufficient to compare the figures of these species 

 in Swainson's ' West African Birds ' and in the ' Ibis.' It is really 

 not necessary to compare actual specimens. An ornithologist of 

 three days' experience will discover the truth of what we have just 

 demonstrated. 



" Fine specimens of both these birds are in the Bremen collection. 



" By-the-by, I must say with Swainson that I cannot subscribe 

 to the opinion that the laminae in the naked part of the long pen- 

 feathers in M. longipenriis have been rubbed or worn off. M. longi- 

 pennis is a common bird in collections. Amongst dozens of speci- 

 mens examined by me I have never seen a bird where the naked parts 

 of the shaft have shown a trace of webs. What may(?) be true in 

 Prionites &c. is, I believe, not applicable to these Caprimulgi. 



"When Prof. Schlegel in the same communication pretends that 



