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PACIFIC SCIENCE, Vol. XIII, July 1959 
Fig. \2b. Charging from the water and accompanied closely by her pup, a mother monk seal leaves the water 
to threaten the photographer. Midway Atoll, May 4, 1957 (KWK 57-17-25). 
days all permanent lower teeth were erupted. 
In the upper jaw, the canines and incisors had 
erupted but only the posterior (fifth) post- 
canines showed. By the age of 46 days, all 
teeth were approximately 3 to 5 mm. above 
the gums. 
The adult dentition is (I 2/2, C 1/1, 
PC 5/5) X 2 = 32. 
Pelage and Molt 
NATAL PELAGE: On Eebruary 27, an aborted 
9-pound fetus was found. It was covered 
winh soft black hair, 3 to 6 mm. long, which 
was slightly and variably curled, giving the 
surface an irregular ridged appearance. The 
first three digits of the right front flipper were 
tipped with white, and there was a small white 
patch on the belly. 
At birth the pup is covered with soft coal- 
black hair 4 to 8 mm. long, appearing almost 
velvety, except that the direction of growth 
can be felt by rubbing with the hand. Rarely 
a flipper is white tipped at birth but this 
feature disappears with the first molt. 
POSTNATAL MOLT: Four male pups (MS-9, 
10, 12, and 13) were observed at frequent but 
irregular intervals of several days or weeks 
from birth to the age of more than 2 months. 
The rate of molt varied somewhat among 
individuals. The size of the mother, at the 
time the pup is born, influences the growth 
of the pup, and thus indirectly the rate of 
molt. The pup of a female of maximum size 
reached a large size before weaning and com- 
pleted its molt more quickly than a pup that 
was weaned earlier and at a smaller size by a 
thinner mother. 
The natal hairs fall out individually, not 
attached to pieces of cuticle as in older ani- 
mals. The new hair grows in first on the face, 
chest, neck, and sides. The last areas to lose 
the natal coat on several pups were the lower 
back, sides of the abdomen, mid-ventral pos- 
terior, abdominal area, and hind flippers. 
At age 20 days, a whitish tinge is evident on 
the muzzle. Light hairs, hidden beneath the 
black coat, protrude above the surface of the 
skin, particularly on the neck and chest. At 
this stage, the black body hair may be pulled 
out without difficulty. At age 30 days, the 
black hair is falling rapidly. When we handled 
the pups, our hands became coated with hair. 
