Final answer:
The class that includes cephalopods in Phylum Mollusca is called Cephalopoda, characterized by their intelligence, complex eyes, and specialized locomotive tentacles.
Step-by-step explanation:
The class that includes cephalopods in Phylum Mollusca is named Cephalopoda. This class encompasses marine organisms such as the nautilus, giant cuttlefish, reef squid, and the blue-ring octopus. Cephalopods are known for their intelligence, vivid coloration used for camouflage, and their sophisticated nervous system. They are bilaterally symmetrical, carnivorous predators with beak-like jaws and a radula. The foot of these organisms has evolved into tentacles and a funnel, equipping them for effective locomotion. Their blood circulatory system is closed, meaning that their blood flows entirely within vessels, a unique characteristic among mollusks. Notable features of cephalopods include their well-developed, image-forming eyes and large brains relative to their body size, making them some of the most intelligent invertebrates. For those with shells, such as the nautilus, the shell can be chambered and used to regulate buoyancy.