STUDIES ON DEROPRISTIS INFLATA (MOLIN), ITS LIFE HISTORY AND AFFINITIES TO TREMATODES OF THE FAMILY ACANTHOCOLPIDAE

¹ From Purdue University, Oklahoma City University, and the Marine Biological Laboratory, Woods Hole, Mass.

The life history of Deropristis inflata has been demonstrated experimentally. The cercaria is a trichocercous form developing in simple rediae in the marine snail, Bittium alternatum. It enysts in Nereis virens and the eel, Anguilla rostrata serves as the natural definitive host which becomes infected by eating annelids containing metacercariae.

The genus Deropristis and Dihemistephanus sturionis are excluded from the family Acanthocolpidae which is redefined to include for the first time the genera Lepidauchen, Pleorchis, and Pseudolepidapedon. The family Pleorchiidae thereby becomes invalid.

It is proposed that the family Allocreadiidae be restricted to include only forms known or believed likely to have ophthalmoxiphidiocercariae with main excretory tubules not reaching the cephalic region of the body before receiving secondary tubules. The Allocreadiidae and Acanthocolpidae are regarded as separate but closely related families.

The genus Anallocreadium is reduced to synonymy with Homalometron and the subfamily Anallocreadiinae is renamed Homalometrinae. The Lepocreadiinae, Homalometrinae, and new subfamily Deropristiinae are regarded as a distinct family, the Lepocreadiidae. The family Gyliauchenidae is believed to be nearer the Lepocrediidae than the Paramphistomoidea. Whether the Allocreadiidae, Acanthocolpidae, Opecoelidae, Lepocreadiidae and Gyliauchenidae constitute only one or more than one superfamily is not apparent from the fragmentary knowledge of life histories and embryology.