636 Transactions.— Geologij. 



Meionoenis casuarinus. 



Dinornis casuarinus and D. rheides, Owen. 

 Mcionoruis casuarinus, Haast.'" 

 Avoinalopteryx casnarina, Lydekker. 

 Syornis casuarinus and S. rheides, Hutton. 



The number of leg-bones measured was — metatarsi, 327 ; 

 tibiffi, 301 ; femora, 276. The sternum has a width below the 

 costal border of 5-2in. to 6'8in. The pelvis has a length of 

 16in. to 18-5in. ; the width at the antitrochauters is Bin. to 

 9-7in. ; and the depth of the pre-acetabular portion of the 

 ilium is 4-7in. to 5in. 



I have already explained that the line drawn between the 

 leg-bones of this species and those of E. crassa is artificial, as 

 the two overlap. The large number of bones of this species 

 proves clearly that there are not two sizes, for there is only 

 a single point of concentration in each bone. 



If the metatarsus is the type of D. rheides, then it is the 

 largest form of M. casuarinus. In all probability the skull 

 v,'ith neck in the Wellington Museum, referred to by Pro- 

 fessor Parker as Mesopteryx, sp. b,\ belongs to it, and perhaps, 

 therefore, we should be justified in considering it as a good 

 species, for the skull seems sufficiently distinct. 



Meionornis didinus. 



Dinornis huttonii and D. didinus, Owen. 

 Meionornis didlformis, Haast. 



Anoinaloptcryx didiformis (part) and A. didina, Lydek- 

 ker. 

 Mesopteryx didina, Hutton. 



The number of leg-bones measured was — metatarsi, 72 ; 

 tibiae, 68, femora, 66. The width of the sternum below the 

 costal border is 4in. to i-5in. The length of the j^clvis is about 

 15'5in. ; and its width at tlie antitrochauters is about 7in. 



Here, again, we have only a single point of concentration 

 in each bone, showing that there was no difference in size 

 between the sexes. The tibia is well marked off from that 

 of M. casuarinus, but the other two bones show many mter- 

 mechate varieties. However, M. didmus is distinguished from 

 ill. casuarinus by its relatively longer metatarsus. The two 

 cannot be different sexes of one species, because their distribu- 

 tion is so different. At Enfield, M. didinus was far more 



* In Eicryapteryx rheides, Haast, the metatarsi alone belong to 

 D. rheides ; the rest of the skeleton is partly M. didinus and partly 

 r. inhabilis. 



t Trans. N.Z. Inst., vol. xxv., p. 4, pi. i. 



