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PACIFIC SCIENCE, VoL XIII, July 1959 
the posterior. Dr. Rausch informs us that he 
has separated the specimens into three forms 
as yet unidentified. 
Algae 
Almost all seals observed in the field have 
areas of their pelage tinged greenish by a 
growth of minute green algae, Pringsheimiella 
scutata (Reinke) Schmidt and Petrack (Fig. 
17). According to Yale Dawson, who identi- 
fied it, this algae is a widespread species 
epiphytic on various slender green algae. The 
size and shape of the seal hair seem to be 
ideal for the growth of this plant. This is ap- 
parently the first time it has been found grow- 
ing on the hair of mammals. On the seals it 
grows most abundantly around the eyes, nos- 
trils, and lips, in the axillae of the fore and 
hind flippers, between the digits, and along 
the side of the body. These are the parts of 
the pelage least subject to drying when the 
animals are on land, and for that reason are 
presumably most favorable for the growth of 
the algae. Animals remaining several days on 
land lost the greenish tinge. One very notice- 
able fact is that the yearling seals have a much 
more abundant growth of algae than do the 
adults. Pringsheimiella differs greatly from the 
strands of Enteromorpha reported from the 
grey seal, Halichoerus grypus (Mackenzie, 
1954), and the harbor seal, Phoca vitulina 
(Scheffer and Slipp, 1944), and from Ecto- 
carpus found on fur seals. 
Fig. 17. Growth curves of four male Hawaiian monk seal pups from birth to several weeks after weaning. Dots 
indicate actual weights. Variation in the length of the nursing period appeared dependent on the obesity of the 
mother at parturition, the most obese mothers nursing their pups for the longest period. 
