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



ally, its breadth to length is greater in the latter than in the 

 Tody. In the proportions of limb-bones, the Momotidse and 

 Todidse stand considerably apart as regards length of ulna to 

 humerus, tarsus to femur, tibia to entire leg. In Eumomota 

 the proportional length of the femur to the humerus and of 

 tibia to ulna falls considerably short of what obtains in Todus ; 

 but Momotus precisely agrees with the latter. The Motmots 

 are unlike the Tody as respects length of metatarse to meta- 

 carpus, and of entire leg to entire wing. 



Thus, all things considered, the two families have character- 

 istic points in their skeleton denoting formation of a kind 

 further removed than what I hold signifies generic import. At 

 the same time there is unity of type. Thus the two, as I shall 

 again notice, ought to come under one division or group. 



2. Comparison with the Coraciidce. — Among ^the Rollers we 

 have extremes analogous to what obtains among the Motmots, viz. 

 narrow and broad-skulled individuals. This repetition is exem- 

 plified in Coracias and in Eurystomus &c. I shall lay more stress 

 on Coracias, which exhibits closer resemblances to Momotus 

 than to Eumomota and possibly Prionirhynchus. 



C. garrula aff'ords a familiar example ; and in analyzing its 

 skeleton point by point I observe the subjoined agreements be- 

 tween it and Momotus : — 



Fair arching of the premaxillary region ; situation of the 

 nostril and moderation of culmen ; a considerable-sized orbit ; 

 likeness in parieto-temporal grooving and occipital facies ; in- 

 terorbital and postorbital width ; spongy maxillo-palatines, which 

 meet mesially. The horizontal palatal plates posteriorly are 

 spineless and round off at the corners. 



On the other hand, so far as the skull is concerned, diflferen- 

 tiation and conti-ast are as plainly exhibited in those particulars 

 which I append. 



In Coracias the beak is but half the length of the entire skull. 

 There is no distinct transverse facial hinge, the premaxillary rods 

 running in a wedge-like manner into the prefrontals. The post- 

 premaxillary depth is relatively greater, the anterior moiety of 

 prsemaxillse narrower ; and there is a width and rounding of the 

 top of the beak compared with Momotus. In Coracias there is 



