Specimens of a new species of the trochospiral genus Floresina Revets, 1990, were collected from depths of 10-30 m at Conch Reef in the Florida Reef Tract, USA. This small foraminifer is predatory on Amphistegina gibbosa . It attacks its much larger prey by climbing upon the A. gibbosa's test, drilling as many as 10 holes per attachment site and extracting cytoplasm from several chambers. Prey is killed in 3-7 days or longer, though individuals occasionally survive and fend off the predator. Asexual reproduction by microspheric adults is commonly cytotomous; 5-20 macrospheric young form, presumably by multiple fission, in a terminal brood chamber. That chamber is weakly calcified and is abandoned after reproduction.