Dr. J. Murie on the Motmots and their Affinities. 395 



were at one time associated with it. In Todus we have a bird 

 not half the size of Eumomota ; yet, when the skeleton of the 

 former is enlarged to double its natural dimensions, as I have done 

 in plate Iv., P. Z. S., 1872, an excellent comparison can be in- 

 stituted. This much is at once apparent, that the Motmots are 

 stamped with a positive bond of osteological affiliation with the 

 Tody. Therefore this is one direct line of their affinities. 



The skeletons of Eumomota and of Todus undoubtedly approach 

 each other in the annexed particulars : — 



In shape, relative length, flattening and shallowness of the 

 prsemaxillae ; in position and size of the nostrils ; in ascent 

 and figure of the cranial parts behind ; in condition of post- 

 frontal and zj'gomatic processes; in constitution of the pala- 

 tines and maxillo-palatines ; in the disposition of the pterygoids ; 

 in the mandible as a whole j in four notches to the sternum 

 and in its shape generally; in the nature of the furcula and 

 coracoids; in the relatively short, wide and shallow pelvis; in 

 vertebral numbers ; in torsion of the humerus ; in morpholo- 

 logical development of tarso-metatarse, and especially its extre- 

 mities ; in the proportions of metacarpus to humerus, of tibia 

 to femur, of femur and of tarsus to entire leg; lastly in the 

 arrangement of the toes and syndactyle foot. 



Tlie same genera, nevertheless, in their skeletal characters di- 

 verge by the following gradations : — 



In the proportionate length of the beak to the skull behind, 

 being longer in Eumomota than in Todus ; in the ossific varia- 

 tion of the interorbital septum — a small space only in the former, 

 none in Momotus, and a large one in Todus ; in Todus having 

 a considerable-sized lachrymal, the lower limb reaching to the 

 jugal; whereas in Eumomota and Momotus prefrontal and eth- 

 moidal processes are well developed, and they are only mode- 

 rately so in Todus ; in the latter bird having broad mid frontals, 

 and they are wide in the former ; somewhat the same relations 

 of parts as regards palatal plates ; in the occiput of Todus being 

 more full and rounded, whilst in Momotus and Eumomota the 

 temporal groove is better impressed. The sternal notches are 

 quite open in Todus, but terminally connected or converted into 

 large foramina in the IMctuiots, Of the pelvis, proportion- 



2 p2 



