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bulletin: museum of comparative zoology. 



still there is so great a discrepancy in the measurements, those of wing 

 and tail being like the large bird, those of bill and tarsus like the small, 

 that it is impossible to determine to which species Kuhl's specimen 

 really should be referred. Since Lafresnaye described the large 

 species as Aestrelata diabolica I prefer to restrict the name Aestrelata 

 hacsitata to the small Black-capped Petrel of Guadeloupe. The fol- 

 lowing table shows the difference in size between the two species. 



Measurements in Millimeters. 



L'Herminier's list of Guadeloupe birds {cj. Lawrence, Proc. U. S. 

 N. M., 1878, 1, p. 451) includes both species of Guadeloupe Black- 

 capped Petrels under the names Procellaria diabolica L'Herm. and 

 Proccllaria maupinc/ L'Herm. These species are marked with a cross 

 to indicate that L'Herminier also found them on Martinique. I have 

 no other information in regard to the Black-capped Petrel in Mar- 

 tinique. 



Investigation will probably show that Aestrelata diabolica and not 

 Aestrelata haesitata as here restricted is the American Black-capped 

 Petrel mostly represented in collections. Mr. J. T. Nichols ha? 



1 Ridgway, Nomenclature of colors, 1886, pi. 17 note. 



2 Determined by Bureau of standards. 



