536 



PROCEEDINGS OF THE XATTOXAL MUSEUM. 



VOL. 42. 



the size of Florida birds, in the females averaging smaller than 

 Florida females. These differences, however, seem too slight and 

 unsatisfactory for siibspecific recognition, because there are alto- 

 gether too many individuals in each of these two series that are 

 inseparable from individuals in the other. Furthermore, the resi- 

 dent birds of western Mexico, north along the coast as far, at least, 

 as San Bias, Tepic, are, although averaging almost unappreciably 

 paler below, practically the same, so far as we can discover, as those 

 of New England; and the same is true of specimens available from 

 southern Mexico, including Yucatan, from Guatemala, British Hon- 

 duras, and Honduras. In size of both male and female, the birds 

 from these Mexican and Central American localities are identical 

 with those from Florida. The birds of all these locahties, from 

 Florida to Texas, Mexico, Guatemala, and Honduras, are seen to 

 be really intermediate in size between Butorides virescens virescens 

 and the Panama race hereinafter separated as Butorides virescens 

 hypernotius;''^ and upon size (which is the only diagnostic charac- 

 ter separating these two races) might with propriety be called 

 either B. v. virescens or B. v. Jiypernotius; yet owing to the interrup- 

 tion of range, at least in western Nicaragua, caused by Butorides 

 virescens mesatus,^ they are seemingly better referred to the northern 

 Butorides virescens virescens, at least until the status of the bird 

 from eastern Nicaragua be determined. The identity of the form 

 occurring on Ruatan Island, Honduras,^ and Cozumel Island, Yuca- 

 tan,^ is somewhat doubtful, as we have seen no specimens from 

 either locahty, but the bird probably is that of the adjacent coast, 

 that is, Butorides virescens virescens. The differences of size in vari- 

 ous parts of the range of this subspecies may be readily appreciated 

 from the following table of average measurements : 



Localities. 



Middle 

 toe. 



Fourteen males, from Pennsylvania, New Jersey, Ma- 

 ryland, District of Columbia, Virgmia, and Kansas. . 



Ten males, from Florida (mainland), southern. Ala- 

 bama, and southern Mississippi 



Twelve males, from the Dry Tortugas, Florida 



Three males, from southern Texas 



Two males, from Tamaulipas and Vera Cruz 



Four males, from Tepic, Colima, Guerrero, and Chiapas 



Thirteen females, from New York, Pennsylvania, New 

 Jersey, Maryland, Virginia, Indiana, Missouri, and 

 Kansas 



Nine females, from Florida (mainland) and southern 

 Alabama 



Two probable females, from the Dry Tortugas, Florida. 



One female, from southern Texas 



Seven females, from Tamaulipas, Vera Cruz, and Ta- 

 basco 



Three females, from Tepic, Guerrero, and Chiapas 



mm. 

 45.0 



45.0 

 45.7 

 43.3 

 44.8 

 45.8 



45.7 



44.7 

 44.0 

 43.5 



43.4 

 45.0 



I See p. 549. 



2 See p. 548. 



3 Sharps, Cat. Birds Brit. Mus., vol. 26, 1898, p. 190. 



