Trunk up to 0.5 mm long, flattened and oval (Fritillaria gracilis). Mouth simple. Spiracles circular. Axis of the alimentary tract almost transverse. Testis curved, parallel to the genital border of the trunk. Testis sometimes divided at its median line (Tokioka, 1955; Dadon and Esnal, 1995), making the specimens very similar to the young of Fritillaria charybdae. Two ovaries at each end of the testis.
Kingdom Animalia Phylum Chordata Subphylum Urochordata Class Appendicularia Family Fritillaridae Subfamily Fritillarinae Genus Fritillaria Subgenus Acrocercus Species Fritillaria gracilis