STUDIES ON TREMATODES OF WOODS HOLE: THE LIFE CYCLE OF LEPOCREADIUM SETIFEROIDES (MILLER AND NORTHUP), ALLOCREADIIDAE, AND THE DESCRIPTION OF CERCARIA CUMINGIAE N. SP.

Abstract

The rediae and cercariae of L. s. develop in the digestive gland of the snail, Nassa obsoleta the cercariae encyst in annelids, Spio sp., and in the turbellarian, Procerodes war-reni the adult worms develop in the intestines of sand dabs and flounders. The structures of the various stages in the life cycle are described. The cercaria contains 24 flame cells in groups of 3 on each side of the body.[long dash]Cercaria cumingiae develops in simple sporocysts in the clam, Cumingia tellinoides, which also serves as the 2d intermediate host. The cercaria possesses peculiar lappet-like structures on the tail. The flame cell formula is 2[(2+2) + (2+2)]. After exptl. feeding, young but still immature worms were recovered from the intestine of the flounder.