74 PTERYLOGRAPHY. 



ring is situated upon each joint, and between these one or two larger ones. On the posterior 

 surface a soft warty skin is always observed at the upper part on the heel, and at the lower part 

 near the toes ; but between these two points there are usually scutes. Most commonly there are 

 two long, narrow, linear plates, placed upon the hinder surface of the tarsus in such a manner that 

 they meet at an acute angle, and are covered in front by the margins of the anterior scutes. 

 Superiorly they are in contact with the heel joint ; below they do not quite reach to the hinder 

 toe, and here one or two smaller scutes are frequently superadded to them. This structure may 

 be regarded as that of the true Passerine type, as it occurs in most of the genera, probably always 

 in Corvus, Glaucopis, Paradisea, Epimachus, Sombycilla, Tanayra, EupJtonc, Fringilla, Loxia> 

 Emberiza, Ploceus, Cassicus, Icterus, Sturnus, Pastor, Buphaya, Oriolus, Lanius, Tliamnophilus, 

 Sethylus, CMepyris, Mascicapa, Edolius, Lamprotornis, Turdus, Ixos, Accentor, Malurus, Grallina, 

 Motacitta, Anthus, Saxicola, Sylvia, Ret/ulus, Pans, Troglodytes, Cinchis, Pitta, Myiothcra, 

 Anabates, Sitta, Dendrocolaptes, Certhia, Philedon, Ncctarinia, Ccereba, and Hirundo, Never- 

 theless, a considerable number of genera do not possess this structure. In the first place, when 

 this foot becomes thicker and plumper, as in Promerops Cuv., Gracula (Eulabes Cuv.), and 

 many species of Sturnus and Lanius, the posterior sharp edge in which the two hinder plates 

 usually meet disappears, and there is found in this place a series of exactly the same elliptical 

 scales or warts which occur above and below at the heel and the point of articulation of the toes. 

 Still more remarkable than this is the structure of Alauda, Pteroptochus, and Jfcnura, in which 

 two rows of scutes make their appearance instead of the two long plates. Of these the inner row, 

 especially below, consists of very narrow elliptical scutes. In a third modification this inner 

 row of scutes entirely disappears, and the outer one leaves only a trace of its existence, in the form 

 of six or seven large oval scales, whilst the whole of the remainder of the posterior surface is 

 covered with small, elliptical, umbilicate scales. I find this structure in Psaris (Lan. cayanus, 

 validus), Muscicapa plumbea, animosa, andferox, and some others. A fourth and last modifica- 

 tion is shown in the complete absence of all large scales among the small, elliptical, umbilicate 

 ones which cover the whole hinder part of the tarse. This structure is the predominant type 

 among the Ampelidfe, especially in Coracina, Cephalopterus, Gymnoccphalus, Chasmarhynclius, 

 Ampelis, Eurylaimus, Calyptomene, Rupicola, and PJtibalura. Eurylaimus corydon, however, 

 presents an exception, as this species, on account of its very thick tarsi, possesses a series of 

 parallelogrammatic scutes between the scales, exactly upon the hinder edge, which are wanting 

 in the other species. The genera above mentioned are in general distinguished by thick tarsi, 

 and therefore the posterior scaly clothing is very broad. When the tarsus becomes more slender 

 the scaly covering becomes narrower, and then consists only of two or three rows. I find it in this 

 form in P/tiledon auricularis and Synallaxis setaria. The latter is the only species of its genus 

 that I have been able to examine. 1 



Finally, I have to remark, with regard to the nest-plumage of the Passerinse, that, as is well 

 known, it does not consist of down-feathers, but of long, hair-like structures, which are seated 

 upon the apices of the uppermost barbs of the very young contour-feathers. They appear as a 

 very light, yellowish, hairy or bristly clothing, first of all on the two sides of the head, on the 

 humeral tracts, and on the saddle of the spinal tract, and make their appearance somewhat later 



1 This description of the tarsus of the Passerine birds is founded upon my own investigations 

 on the specimens in the collection of the University of Halle. B. 



