448 BIRDS OF THE REPUBLIC OF PANAMA — PART 2 



Todd separated the motmots of this group from Costa Rica under 

 the subspecific name costaricensis on the basis of larger size and 

 a few differences in coloration. The considerable series now avail- 

 able from Panama and Colombia show equivalent variations in color 

 that match those he described. The supposed distinction in size 

 also is covered. Todd lists the following measurements from Costa 

 Rica: Males (3 specimens), wing 154-155, tail 284-315, bill 47-52, 

 tarsus 31-34 mm. Females (4 specimens), wing 147-153, tail 250- 

 288, bill 45-48, tarsus 30-32 mm. Measurements from the series 

 from Panama are given above. The following are from our speci- 

 mens from Colombia: Males (19 specimens), wing 142.7-155.8, tail 

 231-280, culmen from base 44.2-57.7, tarsus 29.8-33.5 mm. Females 

 (15 specimens), wing 140-151.1, tail 229-268, culmen from base 

 42.3-50.5, tarsus 29-32.9 mm. The only difference of any marked 

 extent is in the length of tail, which is too highly variable to be 

 of value, due to individual differences and to wear. 



The more northern forms of this group, in which the anterior 

 under surface from the throat down over the breast is wholly tawny- 

 brown, have been listed as races of the more southern Baryphthengus 

 ruficapillus in which the foreneck and breast are plain green. In 

 the latter also the tail does not have the racket tip. Though the 

 birds of this genus all are obviously closely related, the differences 

 mentioned are so definite that two allied but separate species are 

 indicated. 



MOMOTUS MOMOTA (Linnaeus): Blue-crowned Motmot, Pajaro- 

 raqueta de Coronilla Azulada 



Figure 54 



Ratnphastos momota Linnaeus, Syst. Nat., ed. 12, vol. 1, 1766, p. 152. (Cayenne.) 



Large ; crown black centrally, bordered with light to dark blue ; 

 black spot on lower foreneck edged narrowly with greenish blue. 



Description. — Length 360-420 mm. Twelve rectrices. Adult 

 (sexes alike), forehead, lores, and band through eye to auricular 

 region (where it terminates in a point) black, bordered below and 

 on upper margin of auricular area by a line of light greenish blue ; 

 center of crown black, bordered all around by light greenish blue, 

 this in turn edged with violet-blue around the posterior margin (the 

 blue-tipped feathers black at base) ; back to upper tail coverts olive- 

 green ; tail green to bluish green, more blue distally, with racket tip 

 blue tipped with black ; wings green, more or less bluish on outer 

 webs of primaries; under surface, varying according to race, from 



