Odd classes in my heap

Using a custom profiler agent I dumped the contents of our JVMs heap, I was surprised to find some odd named classes consuming a lot of memory, the figures are in bytes:

B = 29580000

D = 29737104

long = 30810800

byte = 30935192

I = 36687024

C = 56404104

S = 62654920

int = 74356440

char = 77453728

My question is are these classes (B,D, I, C and S) part of the JVM or do they belong to a thired party application?

[501 byte] By [Balavaa] at [2007-10-2 21:10:31]