34 Leach, The Myology of the Bell-Magpie. \_^^ 



Emu 



July 



153. The depressor-coccygis [61J [62] arises from the posterior 

 edge of the ischium and post-pubic element of the pelvis. Its 

 fibres converge and form a narrow muscle, which is inserted into 

 the lower portion of the pygostyle. 



154. The lateralis caudce [60] [62] has, as Shufeldt described, 

 four fasciculi, the outer being most distinct. It arises from the 

 transverse process of the first caudal vertebra and is inserted on 

 the outer side of the outer rectrix. The other fasciculi arise from 

 succeeding caudal vertebrae and are inserted into the under side 

 of the quill butts of the three outer rectrices. 



155. The lateralis coccygis [59] arises from the posterior end 

 of the ihum and the caudal vertebrae. It runs down to blend with 

 its fellow over the ventral surface of the pygostyle in a white 

 glistening fascia. It is attached to the under surface of the 

 pygostyle, except the midspine. 



156. The infracoccygis [59] arises from the diapophysis of the 

 last sacral vertebra and also from the caudal vertebrae. It merges 

 with its fellow, and runs backward, converging to be inserted into 

 the midspine of the pygostyle. 



The Pterylosis of Strepera (Plate III.) 



The pterylosis or arrangement of the feathers on a bird was 

 first studied by Nitzsch, whose important work on " Pterylography," 

 edited by Burmeister, was published in 1833, after the death of 

 the author. Fortunately, the Ray Society in 1867 published 

 a translation of Nitzsch's " Pterylography," edited by Dr. Sclater. 

 Strepera, Gymnorhina, and Cracticus agree closely in the feather 

 tracts ; Corvtts differs in having an apterium, or space without 

 feathers, in the centre of the dorsal feather tract. This is an 

 important difference. The primaries are ten in each case ; the 

 tenth or outermost is the shortest. There are eleven secondaries, 

 and the eleventh or innermost is very short in each genus. The 

 fifth cubital or secondary is present in all the birds examined, 

 so that these birds have a quincubital wing. 



The fifth cubital is present in Passeres, Colius, Humming-Birds, 

 and Nightjars. It is variable in Kingfishers and Swifts, and is 

 absent in many widely-separated groups, including, amongst 

 others, Anseres, Herodii, ColumbidcB, Accipitres, Psittaci, and 

 Striges. 



Goodchild (" Proceedings Zoological Society," 1886, pp. 184- 

 203) has found the arrangement of the wing coverts uniform in 

 the chief groups. 



The wing coverts are arranged in the usual Passerine manner 

 in these birds. The greater coverts of the secondaries do not 

 exceed half the length of the corresponding secondary, and they 

 overlap with the proximal edge covered by the feather next 

 inside it. The median coverts have the distal edges overlapped 

 by the feather in front of each. Passerine birds and Woodpeckers 

 have this arrangement. The tenth primary is considerably 



