246 PEOFESSOE OWEN ON THE GENUS DIN OEMS. 



of the outlet of 1 inch 3 lines, and one of the inlet of 10 lines ; through the latter the 

 bodies of the tenth, eleventh, and parts of the ninth and twelfth vertebral centrums 

 are visible. 



Thus the pelvis of the smallest known species of Dinornis repeats, in the main, the 

 characters of that part of the skeleton in the larger species above referred to. It 

 includes the same number of vertebrae as that of Binornis giganteus^. As in this 

 species and D. rolusfus, the pelvis is broader in proportion to its length than in the 

 jijJteri/x, but in most other respects resembles the pelvis in that bird more than it 

 does that of any other known avian genus. The pelvis is equally divided lengthwise 

 at or by the coalesced pleurapophyses of the seventh and eighth vertebrae, giving origin 

 to the ischia, whereas in Struthio^ the part of the pelvis behind this origin is twice as 

 long as the part in front. The terminal junction of the ischium with the pubis, which 

 does not take place in Dinornis parvus, is more extensive and complete in Struthio than 

 in Apteryx^ ; and the pubis in Struthio is extended much beyond that junction, where 

 the ischium terminates. It need hardly be remarked that the produced pubes bend 

 downward and inward, expanding to a symphysial union in the Ostrich, since this 

 mammalian character is peculiar to it among birds. 



It appears that in Binornis rohustus the terminal junction of ischium and pubis is 

 as well marked as in the Apteryx, and that the distance between the ischium and 

 ilium, posteriorly, is less. In Binornis parvus, as in B. rohustus, the terminal expanse 

 of the ischium is relatively greater than in Apteryx, and the interspace between it and 

 the ilium is less; and this narrowing is increased in B. rohustus as compared with- 

 B. parvus. 



If the anterior end of the pelvis oi B. parvus (PI. LIII. fig. 3) be compared with that 

 oiAptornis, the preaxial surface of the first sacral is less extended transversely, the hypa- 

 pophysis is wanting, and the neural spine springs more abruptly from between the 

 prezygapophyses in the present Moa. 



If the same view be compared with that of Cnemiornis, the vertical contraction of 

 the preaxial surface in the latter is still more marked ; the diiFerence in the origin of 

 the long neural spine is the same as in the comparison with Aptornis. In this genus, 

 as in Cnemiornis, the ischiadic notch is converted into a foramen by confluence of the 

 ischium with the ilium ; and such confluence is greater in Aptornis than in 

 Cnemiornis^. 



As the osteology of Bidus is recorded and illustrated in the Gth and 7 th volumes of 

 the 'Transactions' of the Zoological Society, I may here add to the comparison of 

 Binornis with other genera of extinct birds deprived of the power of flight, that of 

 Bidiis in relation to the pelvis. It includes sixteen coalesced vertebra;, with which the 



' Trans. Zool. Soc. vol. iii. 1839, pi. xLx. fig. 4. ' Op. cit. vol. iii. pi. xix. 



' 0^). cit. vol. ii. pis. liv, & It. 



