Larval trematodes of marine gastropods from Galveston Island, Texas.

A total of 3957 gastropods of 20 species including 16 genera were collected from 13 locations in the vicinity of Galveston, Texas from October 1970 to March 1972. Larval trematodes of 15 species were found from 8 species of gastropods. They included: one ubiquita cercaria from Littorina irrorata;, 3 magalurous cercariae from Littorina irrorata; 3 megalurous cercariae, 2 from L. irrorata and 1 from Cerithidea pliculosa; 2 armate cercariae, one from each of L. irrorata and C. pliculosa; a megaperid cercaria from Crepidula plana; a brevi-furcate apharyngeate cercaria from C. pliculosa; 2 eschinostome cercariae, one from each of Thais haemastoma and Nassarius vibex; a magnacercous cercaria from C. pliculosa; a trichocercous cercaria from Anachis avara; and 2 species of unknown family or cercarial type from each of Melampus bidentatus and Polinices duplicata.