FAMILY CRANCHIIDAE PROSCH, 1847

(37 SPECIES IN 14 GENERA)

Diagnosis: Ammoniacal and muscular Cranchioidea with the head fused to the mantle through the nuchal apparatus and the funnel–mantle locking apparatuses; buccal connectives attached to the ventral borders of ventral arms; tentacles with carpal locking apparatus; with a coelom transformed into a buoyancy chamber filled with ammonium chloride; digestive gland usually spindle shaped; most paralarvae with stalked eyes.