240 
CHARADRIIFORMES 
FAMILY RYNCHOPIDAE. SKIMMERS 
The skimmers are a small family strongly characterized by having 
the lower mandible projecting far beyond the upper. We have but one 
species of only casual occurrence in Canada. 
SO. Black Skimmer, le bec-en-ciseattx noir. Rynchops nigra. L, 18. Large, 
black and white birds of the east coast, with long mandibles, flattened and deepened like 
paper knives and the lower mandible extending far beyond the upper one (Figure 351). 
Distinctions. Strongly characterized as above. 
Distribution. Tropical and south temperate parts of the American coast. Occurs 
casually as far north as Nova Scotia. 
SUBORDER— ALCAE. SEA-DIVERS 
General Description. The Sea-divers are birds fitted for sub-aquatic pursuits. 1 he 
hip-joint is set far back on the body and the leg mechanism is better fitted for swimming 
than for walking. The toes are completely (Figure 352) webbed, but lack the kind toe. 
The wings are small in comparison with the size of the body. 
The bill is straight and usually tapered, moderately long 
(Figures 355 to 361); but occasionally flattened and deep- 
ened, as in the cases of the auks and puffins (Figures 353, 
354, and 367 to 371); in the latter group this specialization 
reaches its highest development in the order. 
Distinctions. Toes, three, entirely webbed. 
Field Marks. Small wings and tail; and straight, nar- 
row bills— not duck-like. The divers bear a superficial 
resemblance to ducks, but where ducks would fly they 
dive. 
Nesting. In the immediate vicinity of water on reedy 
shores or rocky ledges, or crevices and holes in the ground. 
In consequence of the peculiar leg construction, an unusually upright 
carriage of body is necessitated when on land, and the birds walk with diffi- 
culty. Indeed some species are almost helpless on the ground and are 
unable to rise into the air except from the water, off steeply rising ground, 
or against a strong head wind. They swim and dive with ease, and, 
though their wings are small in proportion to the size of the body, when 
once on the wing they fly with rapid beats, swiftly and strongly, in straight 
lines or long curves without evolution or manoeuvring. 
Economic Status. The diving birds feed almost entirely upon aquatic 
life, usually captured by diving and pursuit under water. Economically, 
they are of slight importance. 
Subfamily — Plautinae. Great Auks 
As there is but a single well-characterized species in this subfamily, 
and that one is now extinct, see following species for description. 
33. Great Auk. gare-fowl. le grand pingouin. Plautus impennis. L, 30. 
The Great Auk was the largest of the American clivers. Its wings were so reduced in 
size that though they made excellent swimming organs they were useless for flight. As 
the species is now extinct no further description is necessary. 
