AVES. 
209 
colour, but lighter; head and throat mixed with gray; bill 
dusky; legs and toes scaly and black. Twenty-one inches long. 
Inhabits the North Seas. 
Genus 7.—P RO CELL ARIA. —Linnceus. 
Generic Character. — Bill broad, and laterally compressed at 
the base ; point compressed and arched ; both mandibles grooved 
and abruptly inflected towards their points; nostrils prominent 
placed at the surface of the bill, united and concealed in a 
tube, which either forms a single aperture, or tw'o distinct 
orifices ; legs of medium size, but long in some species; tibia 
about half naked; tarsus compressed; three anterior toes en¬ 
tirely webbed and long; hallux represented by a pointed claw' 
only; claw's short, fiat; wings long, first and second quills 
longest. 
Section I.— Petrels. —Bill robust, hooked, bulging towards 
the point; nostrils united in a tube, or furrow', on the surface 
of the bill; tail conical or somewhat rounded. 
Procellaria glacialis. — The Fulmar Petrel. 
Plate LXVI. fig. 1. 
White; back pale gray; bill and feet pale yellow. Sixteen 
inches long. Inhabits the Arctic Seas. 
Section II. — Puffin Petrels. —Bill usually longer than 
the head, slender, much compressed at the tip ; nostrils opening 
in a double orifice near the surface of the bill. 
Procellaria obscura. —Dusky Petrel. 
Plate LXVITI. fig. 11. 
Dusky brown above, very glossy and clouded with umber- 
brown ; white beneath ; sides of breast with transverse brown 
bars ; irides and w'ebs orange; bill and legs yellow'. Fourteen 
inches long. Inhabits the South Seas. 
Section III.— Swallow Petrels. —Bill greatly compressed 
and shorter than the head ; nostrils in a single tube, with two 
orifices; tail square at point or very slightly forked. 
