~ 
one. 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 
haesitata to the small Black-capped Petrel of Guadeloupe. The fol- 
lowing table shows the difference in size between the two species. 
Measurements in Millimeters. 
Bill to Middle Toe 
Angle of (including 
Wing Tail Mouth Tarsus Claw) Culmen 
Kuhl’s specimen com- 306.3: 162.1 42.9 38.1 56.1 — 
puted by Pied du 
Roi! 
Kuhl’s specimen com- 268.71 =142.26 37.54 33.58 49 .39 — 
puted by the Frank- 
furt a. M. inch ? 
Aestrelata diabolica 287 124 46.5 43 55 36 
Mi Ci Ziav3222 
Aestrelata diabolica 288 135 46 42 55 pia) ec) 
MAC EZ wiae2! 
Aestrelata haesitata 264 ILS 42 38 52 Ba. 
M. C. Z. 73219 
Aestrelata haesitata 276 Dore 41.5 ie 51 33 
ME CAZe (e220 
Aestrelata jamaicensts 278 128.5 40 38 Fah Ass 32 
M. C. Z. 73218 
L’Herminier’s list of Guadeloupe birds (cf. 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 
Procellaria mauping 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 has 
1 Ridgway, Nomenclature of colors, 1886, pl. 17 note. 
2 Determined by Bureau of standards. 
