PEOFESSOE OWEN ON THE GENUS DINOENIS. 241 



of breadth to length of the body of the bone are preserved ; but the deep anterior 

 emargination of the Kivi's breastbone is not indicated in any species of Moa of which 

 the sternum is known ; nor have any of them shown the unossified spaces observed in 

 the body of the sternum of some individuals of Apferyx, as in that described in the third 

 volume of the 'Transactions' of the Zoological Society, and figured in pi. xxxix. fig. 2. 

 But, on the whole, the sternum in Dinornis has a closer essential resemblance to 

 that in Apteryx than to that of any of the existing Struthious or flightless birds, as 

 will be shown in the following comparisons. 



In previous Memoirs " On Dinornis," descriptions and figures of the sternum have 

 been given in the 'Transactions' of the Zoological Society. From a mutilated 

 specimen, referred to B. giganteus^, characters were deduced, especially of the anterior 

 and lateral borders, differentiating the bone from that of the Kivi {Apferyx austraJis, 

 ib. fig. 8), and from the sternums of the known existing genera of large wingless birds 

 (ib. figs. 4-7). In a later Memoir^ are given a description and figures of a less mutilated 

 and smaller sternum, repeating the generic characters of the preceding, but differing in 

 the minor breadth as compared with the length ; this subject was chiefly valuable as 

 verifying the conjectural outline restoring the form of the entire bone in B. giganteus 

 in a previous Memoir. 1 am still unfurnished with grounds for positive determination 

 of the species to which the subjects of pi. iv. of the undercited volume can be referred'. 

 In size it accords with that of Dinornis didiformis. The third modification of dinor- 

 nithic sternum was shown by an entire specimen of that of B. rheides*; the fourth by 

 a somewhat mutilated specimen of the sternum of B. elephantopus^ ; a fifth by an entire 

 one of B. robustus, and a sixth by that of B. maximus. 



Of these modifications of the dinornithic type of sternum that (PI. LV.) of Binomis 

 parvus most resembles the subject referred to in note 2. It is absolutely smaller, and 

 is longer in proportion to its breadth, thus making an approach to the form of that of 

 D. rlie'ides, in which the character of length is in excess. 



In the breadth and terminal integrity of the mid production of the hind border 

 (ib. figs. 1, 2, g), the sternum of Binomis parvus resembles that of Z*. elephantopus ; 

 in the minor degree of divergence of the side processes (ib. ib. h, h) it resembles that 

 of B. rJieides. From this it differs in tlie greater relative breadth and minor length 

 of these parts of the hind border of the sternum, in the relative length and breadth 

 of which parts B. parvus more resembles B. giganteus. But the indication of the 

 terminal notch of the mid process (g) is very feeble in the diminutive species; and 

 the foramen above the deeper mid notch of that part in B. rlie^des is wanting in 

 B. parvus. With the figures of the breastbone of the present species (PI. LV.) of 

 the natural size, statement of dimensions may be dispensed with. 



' Trans. Zool. Soc. vol. iii. 1846, p. 316, pi. xliii. figs. 1, 2, 3. ' Ibid. vol. iv. 1850, p. 17, pi. iv. figs. 1-4. 



' Ibid. vol. vii. 1868, p. 116, pis. viii., ix. ' Ibid. vol. vii. pi. viii. 



• Memoirs &c., 4to, 1868, p. 118, pi. viL 



VOL. XI. — PART VIII. No. 2. — January, 1883. 2 p 



