Match the organisms with the appropriate description.
$$ \text {sponges} \quad \quad \text {a. most diverse vertebrates} $$
$$ \text {cnidarians} \quad \quad \text {b. no true tissues, no organs} $$
$$ \text {flatworms} \quad \quad \text {c.jointed exoskeleton} $$
$$ \text {roundworms} \quad \quad \text {d. mantle over body mass} $$
$$ \text {annelids} \quad \quad \text {e. segmented worms} $$
$$ \text {arthropods} \quad \quad \text {f. tube feet, spiny skin} $$
$$ \text {mollusks} \quad \quad \text {g. have specialized stinging cells} $$
$$ \text {echinoderms} \quad \quad \text {h. lay amniote eggs} $$
$$ \text {amphibians} \quad \quad \text {i. feed young secreted milk} $$
$$ \text {fishes} \quad \quad \text {j. unsegmented, molting worms} $$
$$ \text {birds} \quad \quad \text {k. first terrestrial tetrapods} $$
$$ \text {mammals} \quad \quad \text {l. tailless primates} $$
$$ \text {apes} \quad \quad \text {m. bilateral with a saclike gut} $$