LESTRELATA, 63 
Genus ZESTRELATA Bonapartz. (Page 54, pl. XVL,, fig. 6.) 
Species. 
a, sis webs of primaries wholly dusky or with not much more than basal half 
white. 
b'. Plumage largely or chiefly white beneath. 
c. Upper tail-coverts same color as back. 
d', Wing more than 9.00. 
e. Tail ash-gray, the exterior feathers whitish, mottled with 
gray; back, scapulars, rump, etc., plain ash-gray or light 
plumbeous; wings much darker; lower parts white, the 
sides of the chest and neck waved or barred with ash- 
gray. 
J?. Wing 11.50-12.00, tail 5.00-5.90, culmen 1.45-1.50, tarsus 
1.65-1.70, middle toe, with claw, 2.40--2.45; top of 
head almost entirely white. Hab. South Pacific and 
Indian Oceans. 
EZ. lessoni (GaRN.). Lesson’s Petrel.! 
f?. Wing 9.50-10.50, tail 4.50, culmen 1.10, tarsus 1.33, middle 
toe, with claw, 1.75; top of head deep ash-gray, except 
anteriorly. Hab. South Pacific and Antarctic Oceans. 
#2. mollis (GouLD). Downy Petrel.? 
e&. Tail uniform dusky, the exterior feathers sometimes mottled 
with whitish. 
fi. Axillars and under wing-coverts uniform smoky gray or 
dusky. 
g. Culmen 1.25, or more. 
i}, Width of upper mandible at base equal to the 
height of the closed bill at base. 
Head, neck, and chest uniform sooty grayish 
brown, darker above, where nearly the 
same shade as the uniform dark sooty 
color of the upper parts generally ; entire 
sides, flanks, and outer webs of exterior 
lower tail-coverts sooty grayish brown, 
like under surface of wing; rest of lower 
parts white; wing 11.10, tail 4.70 (gradu- 
ated for 1.40), culmen 1.28, width of bill 
at base .65, depth .65, tarsus 1.75, middle 
1 Procellaria lessoni Garnor, Ann. Se. Nat. vii. 1826, 54, fig. 4. Zistrelata lessoni Cass., Proc. Ac. Nat. 
Sci. Phil. 1862, 327. . 
2 Procellaria mollis Goutp, Ann. & Mag. N. H. xiii. 1844, 363; B. Austr. vii. pl. 50. @etrelata mollis 
Covzs, Proc, Ac. Nat. Sci. Phil. 1866, 150, 
