1876.] OF PASSERINE BIRDS. 513 



Through the kind permission of Dr. Giinther I have had the 

 opportunity of dissecting two specimens of each of two species of 

 the genus Pitta, namely P. cyanura and P. angolensis, from the 

 National Collection ; and Mr. Sharpe had previously very liberally 

 given me a specimen of the Javan species, the dissection of which 

 had led me in my paper "On the Carotid Arteries of Birds" to 

 remove it from the Oscines *, as Cabanis had done from its wing- 

 characters. Two specimens of Pitta angolensis from Fantee, and 

 three of P. cyanura from Java, have therefore formed the material 

 for the present description. 



In Pitta angolensis the unmodified trachea terminates thoracicallv 

 in a ring, split behind, and deep in front ; which, from the fact 

 that it presents irregularly placed fenestras on its anterior surface, 

 arranged in a somewhat transversely linear manner, appears to have 

 been formed by the fusion of two rings. This terminal segment of 

 the trachea does not, as iu the Oscines and several other Passeres, 

 form a three-way piece, because there is no antero-posterior bar 

 traversing its inferior margin in the middle line. Of this, however, 

 there is an indication in the form of a median backward-directed 

 process, which advances a short distance into the inferior membrani- 

 form completion of the tube, from its anterior border. The tracheal 

 ring last but one is complete, and has a slight median indentation in 

 its inferior margin behind. These points are seen in Plate LIII. 

 figs. 1, 2, & 3. 



The first and second bronchial ring-segments are semirings — not 

 modified into the somewhat separate, round-margined, slightly 

 oblique semicircles of fibro-cartilage or bone which, as usual, are 

 found nearer the lungs, but are like moieties of true tracheal rings, 

 approximate, sharp-edged, and at right angles to the axis of the 

 tube. They present no peculiar processes, and are slightly swollen 

 at their anterior extremities. 



There is only a single pair of bronchial muscles, continued down 

 from the sides of the windpipe ; insignificant in size ; quite lateral, 

 and terminating by being inserted into the middle of the outer sur- 

 face of the second bronchial semiring. 



Pitta cyanura differs from P. angolensis only in detail, not in 

 plan of conformation. There are four instead of two syringeal 

 bronchial semirings, to the middle of the last of which the single 

 extremely feeble lateral muscle is attached on each side. In it also 

 the last two tracheal rings, and not the last, only, are incomplete 

 behind, the last presenting a greater gap than the one above it. This 

 syrinx is figured in Plate LIII. figs. 4, 5, & 6*. 



Pitta is therefore mesomyodian, in which respect it differs from 

 all the known Old-World Passeres — although Philepitta, with its 

 lengthy first primary, is most probably the same in this respect. 



With reference to other points in the anatomy of the genus, it 



may be mentioned that in both Pitta angolensis and P. cyanura 



there is but one carotid artery, the left. The oil-gland is nude. 



The colic caeca are between one eighth and one tenth of an inch in 



* P. Z. S. 1873, p. 4f>3. 



