I'aeker. — On Notornis mautelli. 



247 



the following table the comparative dimeiasions of the same bones in Notornis, 

 Ocydronms, Trihonyx, and Porphyrio, takmg as a standard the length of the 

 trunk as measured from the centre of a line joining the anterior or dorsal 

 ends of the coracoids to the centre of a line joining the posterior boundaries 

 of the pelvis. This, I think, bears a fairly correct relation to the bulk of 

 the bird, and is independent of the length of either neck or legs. Taking 

 this line as equal to 100, the remaining dimensions may be taken as per- 

 centages of the length of trunk, and thus the proportional size of sternum, 

 pelvis, etc., clearly brought out: — 



Length of Teune=100. 





Notornis. 



Ocydromus. 



Tribonyx. 



Porphyrio. 



Length of sternum 



36 



28 



35 



40 



Width 



24 



14 



17-5 



17 



Depth of carina sterni 



4-8 



4-7 



7 



13 



Length of scapula 



43 



35 



39 



49 



,, coracoid 



22 



20 



22-5 



28 



„ IHum.. 



56 



49 



52 



43 



Width of „ 



29 



21 



22-5 



21 



Length of femur 



57 



51 



49 



51 



Coraco-scapular angle . . 



97° 



100° 



92° 



86° 



Transverse sternal angle 



132° 



141° 



122° 



96° 



PL XX. represents outline drawings to scale of the four skeletons, that of 

 Notornis being two-thirds natural size. 



Vertehral Column. 



In the vertebral column, the nine posterior cervical vertebrge are left : 

 as in Porphyrio and Ocydromus the total number is fifteen and in Tribonyx 

 fourteen,* it is probable that the five or six anterior vertebrse are 

 missing. The last cervical vertebra bears on each side a moveable rib, 3 

 cm. in length, this being proportionally shorter than the corresponding 

 bone in Ocydromus, Tribonyx, and Porphyrio. The penultimate cervical rib 

 is also moveable, but is short and stout, approaching in form to the anterior 

 (ankylosed) cervical ribs. In this particular Notornis agrees closely with 

 Ocydromus. In Porpihyrio and Tribonyx the homologous rib is slender, 

 pointed at its distal end, and fully one-fourth the length of its successor. 



That is, in the single specimen of each at my disposal. 



