Sm ri:i,ni- : Osteoi.ocy ok tiii-: I.i.\iic:<)I..e. 65 



two sterna of the luiropcan W'oodi ock he kindly submitted me for 

 examination, " hut I sentl two to show how variable is the form of the 

 posterior notches in this species ; I have always maintained .that char- 

 acters drawn from this part of the sternum are comparatively of little 

 value, and especially in the Lii/iico/ic.'' 



I now pass to a brief consideration of the osteology of the Jacanas. 



NoTF.s ox THK SKKi.F.roM IN IHK Jacanas (^Tlic Jacanid(c') . 



Jacanas are birds which ha\e been considered by some as belonging 

 to the family RallidcE and by others placed in the present group. 

 Their position here however, I think has now been most definitely 

 settled, chietly through the anatomical investigations upon numerous 

 species of them, undertaken by Garrod and by Forbes. The former 

 writer in his celebrated paper, "On the Value in Classification of a 

 Peculiarity in the Anterior Margin of the Nasal Bones in certain Birds " 

 has said that '■'■ Parra %\iO\\\<\ be removed to the Charadriomorphge," 

 and the last-named talented anatomist in his excellent paper on " Notes 

 on the Anatomy and Systematic Position of the Jacanas {Parridi^).'" 

 has very conclusively settled their taxonomic position for all time. I 

 will use this paper of Forbes quite extensively here for what there is 

 to be said about their osteology. He examined specimens of Parra 

 jacana and gymnostoma, Metopidiiis indictis, africanus and albiniicha, 

 and Hydrophasianus chin/rgi/s, and the present writer has closely 

 studied a mounted skeleton of P. gymiwsfoma. Garrod figured the 

 skull of Hydralector cristata (P. Z. S., 1873, p. 34, Fig. 5), and 

 Forbes the skull of P. jacana (Coll. Sci., Memoirs, p. 224, Fig. i). 



In speaking of them as a family Forbes said in his paper : " There 

 are well-developed basipterygoid processes, which are always absent in 

 the Rails, though of very frequent occurrence amongst the ' Pluviales,' 

 occurring in all the Charadriinge and Scolopacin?e I have examined. 

 In Parra jacana and Metopidiiis albiniiclia, the long, narrow, slightly 

 decurved vomer is emarginate apically, as in certain Charadriidoe. In 

 the Rallidie it is, I believe, always sharp at the point." 



"The maxillo-palatine processes are rather slender and directed 

 backwards ; they have the form of concavo-convex lamellae, are not at 

 all swollen, and do not unite by some way in the middle line, the 

 vomer appearing between and (when the skull is viewed from the 

 l^alatal aspect) below them." 



1 C.anod, .\. H., 1'. Z. S., I.ond., 1S73, pp. 33-3S. See page 37. 

 'Forbes, W. A., I'. Z. S., Lond., 1S81, pp. 639-647. 



