What is clitellum? Give its function.

Explanation

### Step-by-Step Solution:

1. **Definition of Clitellum**:
The clitellum is a specialized, thickened, glandular section of the body wall found in certain annelids, particularly in earthworms. It is typically light-colored and is located in segments 14, 15, and 16 of the earthworm.

2. **Location**:
The clitellum is situated in the anterior part of the earthworm's body, specifically in the segments mentioned above.

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