Step 1: Statement (I)
An ecological pyramid assumes a simple food chain, but in nature organisms are linked in food webs. This is a limitation of pyramids, so Statement (I) is correct.
Step 2: Statement (II)
Saprophytes are left out of ecological pyramids, but they are vital because they decompose dead matter and recycle nutrients. So Statement (II) is incorrect.
Step 3: Conclusion
Statement (I) is correct but Statement (II) is incorrect.
Final Answer:
Statement (I) is correct and Statement (II) is incorrect.
\[ \boxed{\text{(C) }\text{Statement (I) is correct but Statement (II) is incorrect.}} \]