5o8 SHUFELDT. [Vol. XVII. 



Sand grouse, holding, as these latter do, a morphological position 

 directly between them. The plovers are not so far off in 

 another direction, and Tinamtis and Hemipodias have also dis- 

 tant claims to kinship. The extinct dodo and the existing 

 Didunadiis of Samoa are included in the suborder. Fossil 

 remains of pigeons have not as yet been found in this country, 

 though those of turkeys have. 



Taken as a whole, the suborder Cohimbce can easily be 

 divided into two superfamilies — the Didoidce, represented by 

 the extinct dodo {Didus ineptus) of the family Dididce, and 

 the Cohnnboidea, to contain all modern pigeons and such fossil 

 ones as may come to light exhibiting the typical columbine 

 characters in their remains. 



The Cohmtboidea fall naturally into three families — the 

 Gouridcs, the Carpophagidce, and the Cohwibid^s ; and this 

 last, in my opinion, contains as a subfamily the Samoan tooth- 

 billed pigeon, the well-known Didiuiailus strigirostris. A com- 

 plete skeleton of this form I have carefully compared with the 

 skeletons of a variety of pigeons, and am thus enabled to 

 present the following : 



Notes upon the Osteology of Didunculus strigirostris. 



Apart from the skull, this bird has the skeleton of a pigeon 

 that is subtypical but in a very few points. All of the cranial 

 portion of the skull would answer for any ordinary Columba; 

 the principal differences being that in Didimciiltis the inter- 

 orbital septum is entire, and the apices of the post-frontal and 

 squamosal processes of the skull are united by an osseous 

 bridge, agreeing with what is seen in many of the true gallina- 

 ceous fowls {Melagris, for example). 



It is in the facial portion of the skull and in the lower mandi- 

 ble that Didunculus exhibits the greatest differences as compared 

 with other pigeons, and even here the traces of columbine 

 structure are plainly to be seen. The slender zygomatic bar 

 still meets the posterior border of the nasal bone at its middle, 

 while the latter has simply become much broadened and shorter 

 in comparison. 



Schizorhinalism is evident, as in true pigeons, only somewhat 



