FARGOA-BARTSCHI (WINKLEY, 1909) - A LITTLE-KNOWN ATLANTIC AND GULF-COAST AMERICAN ODOSTOMIAN (PYRAMIDELLIDAE) AND ITS GENERIC RELATIONSHIPS

The shell and animal morphology and coloration of the pyramidellid Far goa bartschi (Winkley, 1909) are described. F. bartschi is newly recor ded in shallow water (maximum known depth ca. 30 m) from Massachusetts to Texas. In Massachusetts its host is the serpulid polychaete Hydroi des dianthus (Verrill, 1873). F. bartschi and its congener F. dianthop hila (Wells and Wells, 1961) occur on the same host and sometimes the same worm. The egg of F. bartschi is ca. 58 lm in diameter and the spe cies is ''planktotrophic'' despite its protoconch suggesting lecithotr ophy. The two species are greatly different in size and shell sculptur e but are shown to be closely related. It is argued that shell sculptu re is a poor generic character in pyramidellids.