253 ] 



III. On DiNOENis (Part XX.) : cooitaining a Restoration of the Skeleton of Cnemiornis 

 calcitrans, Ow., with remarks on its affinities in the Lamellirostral group. By 

 Professor Owen, F.B.S., F.Z.S., &c. 



Read December 2na, 1873. 



[Plates XXXV. to XXXIX.] 



§ 1. Introduction. 



In a preceding Memoir ' this genus of the extinct flightless birds of New Zealand was 

 founded upon portions of the skeleton, including some vertebrae of the neck ^, the pelvis^ 

 portions of the sternum ^ indicative of the rudimental state of the keel and consequent 

 incapacity of the bird for flight, a femur ^, a tibia", a metatarsus', and a humerus* 

 described as belonging " to some such flightless bird," and provisionally referred to the 

 species represented by the first-named bones ^. 



The resemblance of the tibia in certain characters to that of a natatorial bird 

 {Colymbus) was pointed out; but there were other features of the bone which checked 

 the choice of the family. The minor degree of inward extension of the inner distal 

 condyle {torn. cit. pi. 66. fig. I, a), as compared with that characteristic of Anatidw — 

 still more the out-springing of the innear trochlear joint at the distal end of the meta- 

 tarsus (torn. cit. pi. 67. fig. 1, ii, and fig. 3, iv) below the level of the interval between 

 the other two trochleae, instead of the inner trochlea rising from a higher level than the 

 origin of the other two trochlese, together with the absence of any backward production 

 of the innear trochlea beyond the plane reached by the other two trochleae, were 

 characters which, in the then (1865) inability to extend my comparisons of these bones 

 with their homologues in the Anatidae, so as to include the rare Australian form 

 Cereo2)sis, counselled reticence as to positive statement of the Anserine afiinities of 

 Cnemiornis, the cranial grounds for determining the family affinities of the genus being 

 wanting. 



These grounds have now been supplied by an esteemed and accomplished corre- 

 spondent, James Hector, M.D., F.R.S., Government Geologist of the province of Wel- 

 lington, New Zealand, from whom, in September last, I received outline figures and 

 brief notes of Cnemiornis in addition to those given in my first Memoir (torn, cit.), or 



' " On Dinornis" (Part S.) &c., Trans. Zool. Soc. vol. v. p. 395. 



' lb. pi. 63. figs. 1-4, pi. 64. figs. 1 & 2. =■ PI. 64. figs. 5, 6, 7. * PI. 63. figs. 5, 6, 7, 8. 



' lb. pi. 6.5. figs. 1 & 2. ' lb. pi. 66. figs. 1-5. ' lb. pi. 67. figs. 1-4. 



' lb. pi. 66. figs. 7-10. ' lb. p. 396. 



VOL. IX. — PART in. May, 187b. 2 m 



