do not contain inclusions, although small bubbles and/or 
small plant fragments are abundant in some specimens. 
Most unbroken specimens are small (one-eighth inch in 
diameter) teardrop masses, subcylindrical pieces up to 
one-fourth inch in diameter or irregularly mammillary 
blobs. The teardrops may have dropped from the trunk 
or branches, and the cylinders may have broken from 
hardened runnel of resin attached to the surface of a 
branch. All of these shapes tend to demonstrate resin 
hardened in the atmosphere. Several occurrences of am- 
ber in coal with woody texture, however, suggest that at 
least part of the amber was derived from resin within 
the trunk of tree and thus not in a position to trap in- 
sects or wind-blown plant debris. 
Twenty-two spectra were run of Alaskan amber rep- 
resenting samples varying in color and other physical 
properties. Nineteen specimens were from the Kaolak 
River and three from the Ketik River localities; none 
were available from the Kuk River. Most of these col- 
lections were from placer deposits, although at two locali- 
ties the amber was collected im situ. All of the material 
is from the collections of the Museum of Paleontology, 
University of California at Berkeley. Three patterns 
appeared among the 22 spectra run (Plates XIV and 
XV). The most typical pattern is Type II (H-382); 15 
spectra are of this kind. The spectra typical of amber from 
the Raritan formation from Kreischerville, Staten Is- 
land, New York, is similar to Alaska Type II in the 
carbon skeleton. Type I (H-318) is a more generalized 
pattern (i.e., more flattened with less pronounced bands) 
and is represented by three spectra. Type III (H-318 
on Plate XV) occurs only in two spectra but is quite 
similar in the carbon skeleton to that of the amber from 
the Upper Patapsco Formation from Washington, D.C. 
There are, however, differences between the pairs Alaska 
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