No. 3-] THE OSTEOLOGY OF THE PIGEONS. 509 



masked by the extraordinary upper mandible proper. This 

 has the form of the beak of a small raptorial bird, its distal 

 apex being hooked and sharp, and at its base pushed into, as it 

 were, the frontal region of the skull. Indeed, it is the beak of 

 a hawk engrafted upon the face of a dove. From the anterior 

 portions of the palatines at the base of the skull, backwards, 

 the characters are of any ordinary pigeon. Turning to the 

 mandible, we find it much thicker and stronger than it is in the 

 Cohcmb(S generally ; it is nearly of uniform depth throughout, 

 with a strong symphysis of a very strigine look. 



The articular ends agree with some pigeons, but the ramal 

 vacuity does not exist, and this is present in Ectopistes and 

 others. In the dodo the ramal vacuity was very small and 

 inconspicuous.^ 



The osseous Jiyoidean apparatus of Didimculns is extremely 

 slender and agrees with the corresponding parts as seen in 

 Coliimba livia. 



As for the balance of the skeleton of this Samoan pigeon, it 

 is simply after the general columbine type, a slight departure 

 alone being seen in the sternum. This has a great open notch 

 of an elliptical outline upon either side of the keel, — there 

 being no smaller pair of notches posterior to these, as in most 

 all pigeons. But, nevertheless, by holding the sternum of 

 Diduncuhis up to the light, a thinning of the bone over the 

 usual sites for these latter, as found in other representatives of 

 the suborder, is evident. 



In their excellent memoir cited in note below, Newton and 

 Gadow have shown that ^'Cohmtba, Phaps, and Diduncuhts differ 

 from the others {Treron, Carpophaga, Gotira, Pczophaps, and 

 Didiis) in having only twelve true cervical vertebrae,^ two short, 



1 For the best accounts of the osteology of Didus inepttis see the memoir by 

 Professor Owen ( T. Z. S., vi and vii) ; Fiirbringer's Morphologie und Systematik 

 der Vogel (taf. xxi und xxii, pp. 778-781) ; Brown's Thier-Reich: Vogel (p. 950) ; 

 but especially the memoir by Sir Edward Newton and Dr. Hans Gadow, entitled 

 Oft Additional Bones of the Dodo and Other Extinct Birds of Mauritius obtained by 

 Mr. Theodore Sanzier {T. Z. S., London, vol. xiii, pt. vii, p. 296). 



2 These authors consider that " cervico-dorsal vertebras are those which carry 

 movable short ribs," and that " the other neck-vertebrse are true cervical verte- 

 brae ; with the exception of the atlas and the epistropheus, they all possess a 

 transverse foramen and immovable rib-rudiments." 



