Which of the following is not an Annelid?

Classify the phylum Vertebrata into their further groups by giving two characteristics of each.

State whether the following statement is true or false:
$Platyhelminthes$ are either free-living or parasitic.

Which of the following features is not a characteristic of $Protochordata$?

Differentiate between the following (any one point):
$(a)$ Diploblastic and triploblastic animals
$(b)$ Warm-blooded and cold-blooded animals

State reasons for the following:
$(a)$ Mammals have mammary glands.
$(b)$ Annelids have a true body cavity.
$(c)$ Fish possess gills.