FAMILY FALCONIDAE 263 



from a cavity in a large tree and saw another broken stub where the 

 birds were said to nest. In the same account he describes an egg taken 

 in San Luis Potosi from a natural cavity where it lay without lining 

 other than the debris usual in such openings. This egg, subelliptical 

 as shown in an accompanying illustration, had the ground color 

 entirely concealed by a "wash of dark chocolate brown and a few 

 splashes of burnt umber, but there are a few streaks of lighter 

 yellowish brown where the pigment is thinner." It measured 58.0 X 

 44.6 mm. 



There is an egg in the U. S. National Museum collections, long 

 attributed to the collared forest- falcon (Micrashir semitorquatus) 

 that was collected by John Xantus on the "Nishpa Rio" in Michoacan 

 in April 1863. This is between subelliptical and oval and between 

 cinnamon-buff and clay color in ground color, irregularly washed and 

 blotched with chestnut-brown, thickened in occasional irregular spots 

 until it appears almost black. It measures 59.2x43.3 mm. Under date 

 of April 19, 1863, Xantus wrote to Prof. S. F. Baird from the 

 mountains of southern Michoacan that he had collected an egg of the 

 "vaco" from "the hollow top, about 5 feet in the trunk" of a large 

 wild fig tree. He attributed the nest to the collared forest- falcon 

 which he had collected at or near this point, but in evident error. 

 Though the nest and eggs of the latter are unknown, in the numerous 

 specimens of this species that I have handled there has been no 

 evidence whatever of feather wear that is inevitable in any hole- 

 nesting bird with such a long tail. The site, the common name, the 

 form, and color of the egg are those of the laughing falcon. 



There has been uncertainty as to the geographic variation found 

 in these birds, so that the number of subspecies recognized by different 

 authors has varied from two to six. The main difficulty has come 

 from lack of understanding of the considerable amount of individual 

 variation both in color and size. After examination of more than 125 

 specimens I still find it reasonable to recognize the three races that I 

 outlined in a study of more than 20 years ago (Wetmore, Proc. U. S. 

 Nat. Mus., vol. 95, 1944, pp. 35-38). These are Herpetotheres 

 cachinnans chapinani Bangs and Penard, which is more grayish brown 

 above, with the edgings of the dorsal feathering of the immature 

 lighter, brighter brov/n, found from Mexico to northern Honduras 

 and El Salvador; H. c. cachinnans (Linnaeus), darker, blacker 

 above, with the edgings in the immature darker, more chestnut brown, 

 that ranges from Honduras to Peru and central Brazil; and H. c. 

 queribundus Bangs and Penard, which is lighter, more grayish brown 

 above than chapmani, with the edgings in the immature paler and 



