JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. The American Society of Parasitologists is collaborating with JSTOR to digitize, preserve and extend access to The Journal of Parasitology. Navy Medical Research Unit-3 and continued during the ensuing year at the University of Southern California.3 A trip was made to the small fishing villages, Baltim and El Burg, located on the northeastern shore of Lake Burullus where a host of children quickly offered their services for collecting and in a short time they presented us, for a fee, with several thousand snails, Pironella conica Blainville, and over one hundred small fishes, Aphanius fasciatus (Valenciennes). We are indebted to Dr. T. Abbott, U. S. National Museum, for the identification of the snails, and to Dr. Carl L. Hubbs, Scripps Institution of Oceanography, for the indentification of the fishes. These animals were living in brackish or saline water since the collecting site is near the connection of the lake with the Mediterranean Sea.The fishes were heavily infected with metacercariae. Some of the fishes were fed to hatchery-raised chicks and when the chicks were examined by the junior author adult heterophyid worms were recovered. Adult worms also were recovered from chicks that were fed experimentally infected Gambusia affinis. These adult worms and the larval stages obtained from Pironella conica form the basis of this study.
MATERIALS AND METHODSIn early October, 1953, 468 living Pironella conica were shipped in damp sphagnum moss from Cairo to the University of Southern California. Of the 215 survivors, 166 were infected with heterophyids. Naturally emerging cercariae were studied either alive to determine the details of the excretory system or as fixed and stained whole mounts. Redial stages, obtained by crushing snails, were studied after fixation and staining. Metacercariae were dissected from formalin-fixed Aphanius fasciatus. Adult worms were obtained by feeding naturally infected Aphanius fasciatus and experimentally infected Gambusia affinis to hatchery-raised chicks. The Gambusia were infected in the following way. Pironella conica, naturally infected with cercariae of the type described herein as the larval stageReceived for publication, February 21, 1955. * The opinions or assertions contained herein are the private ones of the authors and are not to be construed as official or reflecting the views of the Navy Department or the naval service at large.
