1) Amphibian family 2) Caeciliadae 3) Family caeciliadae 4) Family caeciliidae 1) Caeciliadae 
Caeciliidae is the family of common caecilians. They are found in Central and South America, equatorial Africa and India. Like other caecilians, they superficially resemble worms or snakes. Although they are the most diverse of the caecilian families, the caeciliids do have a number of features in common that distinguish them from other caecilians...
(from the article `Apoda`) ...copulatory organ in males; aquatic larvae (with gill slits but no external gills), direct development of terrestrial eggs, or viviparous; about ...
[n] - coextensive with the order Gymnophiona: legless amphibians
family Caeciliidae noun coextensive with the order Gymnophiona: legless amphibians