AVES. 
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in the ridge and concealed by a membrane; legs short, strong, 
placed far behind ; tarsus covered with feathers at top; three 
anterior toes, and hallux connected by a web, the latter long, 
articulated on the side of the tarsus; claw of the middle toe 
serrated ; wings long, first and second quills longest. 
Sula alba — The Soland Goose. 
Plate LXYII. fig. 1. 
General plumage white; quills and bastard wings black ; head 
and occiput pale sulphur yellow; bill blue, ash-coloured at the 
base, white at the tip ; naked membranes on the ophthalmic 
region, and throat blue ; irides pale yellow ; legs dusky. Two 
feet eight inches long. Inhabits Europe. 
Genus 19.—PLOT US.— Linnaeus. 
Generic Character. —Bill long, quite straight, slender, fusi¬ 
form, and sharp pointed ; edges of upper mandible dilated at 
the base, compressed, and inflected on the other parts ; under 
mandible inflated near the point, and slightly retrousse at the 
tip ; edges of both mandibles finely serrated; face and throat 
naked; nostrils basal, linear, oblong, ovate, situated in the 
groove and concealed; legs short, strong, tarsus partly covered 
with feathers at the top ; feet with three anterior toes, and the 
hallux articulated at the side of the tarsus, the whole connected 
by one web to their points ; nails strong, short, and much hooked; 
wings long, the second and third quills longest; tail conical. 
Plotus melanogaster .— The Black-Bellied Darter. 
Plate LV. fig. 5. 
Dark umber-brown above ; nape and sides of the neck with 
white oblique lines ; lower part of the neck, chin, and upper 
wing-coverts, speckled and longitudinally streaked with white ; 
throat, breast, abdomen, and crissum, black; quills and tail 
black ; the latter with a band of white at its point; upper man¬ 
dible blue, lower mandible dull yellow; feet yellow. Three 
feet three inches long. Inhabits the seas of South America. 
Genus 20.—PHAETON.— Linnaeus. 
Generic Character. —Bill longisb, thick, strong, hard, sharp 
pointed at the edges, greatly compressed, with a slight curvature 
z 
