1972 JOHNSON: FLORIDA UNIONIDAE 241 HABITAT-Lives in mud or soft sand of rivers and lakes, particularly when rich in vegetable detritus. REMARKS.-In peninsular Florida Villosa an!ygdala Lea can only be confused with V. cibex (Conrad) with which it is often found living. The rays of amygdala are narrower, generally sharper, and of a lighter green than those of vibex. The surface of amygdala is generally less shiny, and the shell is more inflated and generally heavier. Sexual dimorphism is more apparant in amygdaloa. The males of both species tend to be some- what pointed posteriorly, but females of amygdala are more inflated, with the posterior margin subangulate dorsallv and broadly truncate below. while females of vibcx tend to be less inflated and more broadly rounded posteriorly, rendering the ventral margin slightly arcuate. Villosa amygdala is most closely related to V. lienosa (Conrad) which is found in the Interior Basin and extends along the Gulf Coast from Texas to the Suwannee River, Florida. Both species show similar sexual dimor- phism, but lienosa has a consistently heavier shell that is less elongate and less inflated than that of amygdala. Unlike the latter, lienosa is infrequently rayed, and usually has a purplish nacre, while that of amygdala is white. V. amygdala is replaced in the Atlantic Slope region from the Altama- ha River system, Georgia to the Neuse River system, North Carolina, by V. delumbis (Conrad), which is similarly sexually dimorphic. V. delumbis has a rather consistently thin shell with a light yellow or light greenish- yellow periostracum covered by narrow green rays that are characterist- ically broken by growth rests. RANGE. - Peninsular Florida SPECIIENS EXAMINED.-WITHLACOOCHEE RIVER SYSTEM: Lake Jovita (Clear Lake), St. Leo, Pasco Co. Lees Lake, Panasoffkee;lake, 6 mi. NNW Panasoffkee; both Sumter Co. Lake Consuelo, near Floral City; Lake Tsala Apopka, Hernando; Withlacoochee River, near Crystal River; all Citrus Co. HILLSBOROUGH RIVER SYSTEMI:-Lake Tarpon, Tarpon Springs; Pinellas Co. Hillsborough River, 4 mi. NE Temple Terrace, Hillsborough Co. PEACE RIVER SYSTEM: Lake Hamilton, 4 mi. SSW Haines City; Polk Co. Silver Lake, Tavares, Lake Co. Horse Creek [De Soto and Hardee Cos.]. Charlie Creek, 3 mi. SW Nocatee; Peace River 1.25 mi. below Arcadia; both De Soto Co. KISSIMMEE RIVER SYSTEM AND EVERGLADES:-KISSIMMEE RIVER DRAINAGE. East Tohopekaliga Lake, Nar- coossee; Lake Tohopekaliga, Kissimmee; Lake Marion, 3 mi. WNW Keansville; all Osceola Co. Lake Rosalie, 4 mi. NE Hesperides; Lake Weohyakapka, Indian Lake Estates; Tiger Lake, 7 mi. ESE Hesperides; all Polk Co. Lake Viola, Avon Park; Bonnet Lake, 3 mi. N Sebring; both Highlands Co. LAKE OKEECHOBEE DRAINAGE. Fisheating Creek, 1 mi. S Lakeport; Caloosahatchee River, above lock, Moore Haven; both Glades Co. Lake Okeechobee, St. Lucie Co. Lake Okeechobee, 2 mi. N Canal Point; canal from Lake Okeechobee [town of] South Bay; both Palm Beach Co. Canal, 10 mi. E Monroe Station; Collier Co. Seven Mile fire tower, 7 mi. S Tamiami Trail, Everglades National Park; Dade Co. Lake Osborne, 2.5 mi. NW Lantana; Palm Beach Co. ST. JOHNS RIVER SYSTEM: ST. JOHNS RIVER DRAINAGE.-Ditch, near Deer Park; Osceola Co. Ditch, near Lake Washington, 6 mi. W Eau Gallie; Brevard Co. Puzzle Lake, 7 mi. SE Ge- neva; Lake Harney, 3 mi. SE Geneva; Econlockhatchee River, near confluence with.