APPENDIX. 161 



shoulders, leaving a wide featherless space. The branches are then discontinuous for a short 



distance, but reappear in two gradually converging lines, which unite on the rump. But here a 



very abnonnal feature presents itself, which is found neither in the Coraciida nor in any other 



family of the Order Picariac. This is two large and highly developed powder-down patches (fig. 5, 



p, p), which are placed on the flanks, on each side of the rump. They 



are of an oval shape, and measure about If inch in length by an inch FIG. ** 



in breadth. The development of these lubricating organs may perhaps 



account for the atrophy and almost total disappearance of the oil-gland, 



which can scarcely be recognised in the minute papilla (o, fig. 5), situated 



at the base of the two medial tail-feathers. 1 



The sternum of Leptosoma (figs. 6 and 7, p. 162), a specimen of 

 which Mr. A. Newton has kindly lent me from his extensive collection 

 of these objects, does not, I must admit, present us with any very close 

 resemblance to that of Coracias. At the same time I do not see that it is 

 in any respect more like that of the Citculida. 



The two posterior fissures so characteristic of the greater number 

 of forms of the order Picarise are here run together, forming but one 

 large opening, the apophysis between them not reaching to the line of the 

 posterior margin, and the outer fissures being smaller and not so deep 



as the inner pair. In Coracias and Eurystomus the outer fissures are deeper, and the separating 

 apophysis advances quite to the posterior margin. There are two other points in which the 

 sternum of Leptosoma differs considerably from that of the Coradidce. These are the very 

 rudimentary condition "of the episternal process (e,p., fig. 7), and the remarkable thickening of 

 the rami of the furcula at their anterior extremities, and their attachment to the front of the 

 coracoid by a massive head. In Coracias and Eurystomus^ the episternal apophysis is well- 

 developed and terminates in a point, which advances some way forward between the coracoids, 

 nor are the rami of the furcula thickened to any noticeable extent where they join the coracoids. 

 It may also be noticed that the coracoids of Leptosoma overlap one another a little at their 

 junction with the sternum, as is the case with some of the Accipitres. 



1 This is, I believe, the first instance of powder-down patches having been noticed to occur in any 

 species of the Order Picarise. Nitzsch (antea, pp. 37, 38) describes them as met with in the 

 following genera : Order. 



Nauclerus . . . . . 

 Elanus . rAccipitres. 



Cymindis . . . . . 



Artamus ..... Passerinse. 



Tinamus ..... Gallinse. 



Ardea and its affines . . . -i 



Cancroma ..... i-Grallae. 

 Eurypga . . . . . * 



Mr. Bartlett has determined their presence in Balceniceps (see antea, p. 165, and Rhino- 

 chetus (' P. Z. S./ 1862, p. 218). 



- Cf. Blanchard, " Recherches sur les Caracteres Osteologiques des Oiseaux/' ' Ann. d. Sc. Nat.,' 

 Zoologie, ser. 4, vol. xi, p. 127. 



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