;"Number of epithelial cell layers";Dorsal;Ventral
"O. albicans";4;4–5
"O. angrensis";4;4–5
"O. flavoguttata";4;4–5
"O. humilis";4;8
"O. perpusilla";3–4;4–5
"O. trapicheroi";5;5
"O. v-signata";4;4
"S. similis";4;4
"S. hayii";4;4–5
"S. x-signatus";5;7