294- TROPICAL WILD LIFE IN BRITLSII (JUIANA 



is a single row of pigmented .slieaths, superimposed by an- 

 other row of covert-like sheaths. These are of specjal inter- 

 est as representing the pelvic wing recently demonstrated 

 by Beebe. ' 



A later embrvo, i)robablv not more than twentv-foui" 

 honrs older, shows a fnrther development of the tail and 

 body tracts. The spinal tract has become pigmented with 

 a light hrown color, its sheaths heing especially developed 

 along the dorsal region, where some eqnal the rectrices in 

 length. Xo other pterylae are pigmented or mnch elongated. 



The spinal tract is quite wide and divided hy a long- 

 cleft above the dorsal and sacral regions which unite at the 

 neck and lower pelvic. The femorals, accentuated by the line 

 of pigmented sheaths and their coverts, are large. They 

 join the crural or leg tract to foi-m a continuous field, which 

 extends over the upper two-thirds of the cms and joins the 

 spinal pterylae behind the humeral tract above, and the ven- 

 tral just below the point of the sternum. 



The two scapular tracts are broad as in the adult and 

 the sternal is divided into two narrow banrls, one on each 

 side of the keel, the space between being very narrow and 

 extending from the point of the sternum to the upper throat. 

 The pectorals are wide and extend from half way between 

 the wing and the cms to the shoulder, where they join the 

 sternal. 



The embryonic pterylosis of the jacana more nearly 

 approaches the Limicoline type than that of the Fulicariae 

 as claimed by Xitzsch. In speaking of the adult birds, 

 Forbes says': "In their possession of well-marked firm rec- 

 trices, in the weakness of the lumbar tracts, and in the tend- 

 ency to a division of the dorsal tract into an anterior and 

 posterior fork, the Parridae differ from the typical Rallinae, 

 and approach the IJmicoline type." These facts are in the 



' 'Aoolojiiid. \'ol. II, Xo. iJ. 



^ Notes on the Anatomy and Systematic I'osition of the Jaeanas ( I'arriilae). 

 Proc. /ool. Soc. London, 1881, page (ilO. 



