Aristotle's lantern is found in the class .......... .

Water vascular system is the characteristic of which group of the following:
$(a)$ Porifera $(b)$ Ctenophora $(c)$ Echinodermata $(d)$ Chordata

In which class of Echinodermata is a stalk found for attachment to the substratum?

The water vascular system is a characteristic feature of which phylum?

Mark the correct combination of Phylum,Class,and Example.

Bipinnaria is the larva of