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PACIFIC SCIENCE, Vol. XVII, July 1963 
The internal temperature is slightly lower in 
the sand-coated than in the naked black speci- 
mens because of the reflection of light and 
heat by the coating of sand characteristic of 
this species. 
6. Evidence of predation upon H. atra or H. 
leucospilota is practically lacking. 
7. Transverse fission in H. atra has been ob- 
served in various stages of progress, and is 
considered to be an important means of repro- 
duction. 
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Cuenot, L. 1948. Anatomie, Ethologie et Sys- 
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Frizzell, D. L., and Harriet Exline. 1955. 
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