APPENDIX. 163 



already stated, has the normal number of five phalanges the first two being very short, each 

 measuring only about 0'5 in. in length. It is articulated not in a directly reversed position, as 

 among the more typical Zyyodactylae, but laterally, rather more behind than in front. It will 

 therefore be seen that Leptosoma, even in this respect, diverges widely from the Cuculida, 

 i(cconid<s, &c., in which the fourth digit is placed in a directly reversed position. 



So much, then, I am at present able to say concerning the peculiarities of this remarkable 

 type. In order to refer Leptosoma decisively to its proper place in the natural series, an 

 examination of the soft parts of its structure still remains to be made, which as yet I have had 

 no opportunity of doing. But it appears to me that sufficient is known to show that Leptosoma 

 can no longer be left as a genus of the family Cuculidce, from which it differs in many important 

 points, particularly in the form of the nostrils, in the presence of an auxiliary plume on the 

 body-feathers, in having twelve tail-feathers, and in the structure of its feet. As far as I can at 

 present form an opinion, a more natural situation for Leptosoma would be as the type of a 

 separate family in the neighbourhood of the Coraciida. The singular structure of the nostrils 

 very much resembles that of Eurystomus. Eurystomus also has the aftershaft, and the same 

 number of tail-feathers although differing from Leptosoma in the form of the sternum and the 

 structure of the feet, so that they could hardly be associated together in the same family. 



I have as yet had no opportunity of seeing more than a stuffed specimen of another singular 

 Madagascar type the Brachypteracias leptosomus ; but I think it very probable, from the super- 

 ficial examination I have made of it, that this, as suggested by Lesson, may be the missing link 

 which connects Leptosoma with the Coraciidte. 



Explanation of the Figures. 



Fig. 1. Head of Leptosoma, showing the projection of the loral and frontal plumes, and the position of 

 the nostrils. 



Fig. 2. Outline of the skull of Leptosoma, showing the position and form of the nasal apertures (a) and 

 the ossified covering (b). 



Fig. 3. Lower surface of a feather from the back of a male Leptosoma, wrth part of the inner web 

 removed, so as to show the auxiliary plume more clearly. 



Fig. 4. Lower surface of a feather from the breast of a female. 



Fig. 5. Upper surface of Leptosoma with feathers removed (reduced), showing the bifurcation 

 of the spinal tract and the position of the two powder-down patches ( p, p) and oil- 

 gland (o). 



Figs. 6, 7, Sternum of Leptosoma. 



Fig. 8. Tongue and hyoid bones of Leptosoma. 



