of the United States . 
351 
63. RHINCOPS. 
Rhincops , L. Gm. Lath. III. Cuv . Vieill. Temm. Ranz . 
Rigcopsalia } Barrere , Brisson . Pkalacrocoraoc, Moehring . 
Bill longer than the head, straight, almost tetragonal at 
base, then exceedingly compressed ; upper mandible much 
shorter than the lower, somewhat curved from the base to the 
point, rather acute at tip, grooved so as to receive the 
edge of the lower ; edges much bent in forming a narrow 
channel ; lower mandible narrower, truncated at tip, lineated 
obliquely on the sides, with the edges distinct only at base, 
being so well united as to appear a mere blade, fitting into 
the channel of the upper : nostrils basal, marginal, concave, 
oblong, longitudinal, open, pervious : tongue very short, 
narrow, acute. Feet moderate, slender; tarsus somewhat 
longer than the middle toe ; middle toe longest ; inner short- 
er than the outer ; webs emarginate ; lateral toes bordered 
exteriorly with a narrow membrane ; hind toe shorter than a 
phalanx of the middle one, articulated rather high on the 
tarsus, touching the ground at tip : nails rather elongated, 
curved, acute ; the middle nail twice as long as the lateral ; 
hind nail much the smallest. Wings extremely long, folding 
across each other, falcate upwards ; first primary longest, 
and with the second much longer than the others. Tail of 
moderate length, forked. 
Female similar to the male. Young differing from the 
adult. Moult twice in the year, but without much changing 
their appearance. 
Keep in small parties near the shores, seldom venturing far 
at sea. Resting on shores and in marshes : walk awkwardly : 
seldom alight, hardly ever on the water ; never swim. Flight 
slow, flapping when looking after food, swift and tortuous 
when it is discovered. Feed on small fishes, and other marine 
animals, skim the water, ploughing it with their lower man- 
dible, the upper being kept out until the prey is felt by 
