Aristotle's lantern is a masticatory apparatus of echinoids.

Answer

**Step-by-Step Solution:**

1. **Understanding Aristotle's Lantern**: Aristotle's lantern is a specialized feeding structure found in echinoids, which are a class within the phylum Echinodermata. It serves as a masticatory apparatus.

2. **Structure of Aristotle's Lantern**: The lantern consists of five calcium carbonate teeth or plates. These plates are arranged in a way that they form a tongue-like structure, which aids in the process of feeding.

3. **Function of Aristotle's Lantern**: The primary function of this apparatus is to masticate or break down food particles. The teeth work together to engulf food and divide it into simpler forms, making it easier for the organism to digest.

4. **Location and Anatomy**: The Aristotle's lantern is located at the mouth of the echinoid, with the anus positioned at the opposite end. The overall structure resembles a lantern, which is how it got its name.

5. **Unique Feature of Echinodermata**: This masticatory apparatus is a unique feature of echinoderms, distinguishing them from other animal groups. It plays a crucial role in their feeding mechanism.

6. **Conclusion**: The statement that "Aristotle's lantern is a masticatory apparatus of echinoids" is true, as it is an exclusive feature of this group within the phylum Echinodermata.

---