Identification of Hyla microcephala tadpoles is relatively simple here in Palo Verde. They are the only species with a long, filamentous tip to their tails. They also have a dark, lateral line, lack denticles, but have a beak. The other Hylidae species here (i.e. Smilisca) are larger, have denticles, and lack a filamentous tail.
Other tadpole posts:
Rhinophrynus dorsalis
Engystomops pustulosus
Incilius luetkenii
Smilisca baudinii
Hyla microcephala
Leptodactylus melanonotus