New archaeogastropod limpets from hydrothermal vents: new family Peltospiridae, new superfamily Peltospiracea

Seven new species of limpets from hydrothermal vents are described in five new genera in the new family Peltospiridae (new superfamily Peltospiracea). Limpets in this family are known only from the hydrothermal vent community at two sites, near 21°N and 13°N, on the East Pacific Rise. New genera and species are: Peltospira , type species P. operculuta from both sites, and P. delicata from 13°N; Nodopelta , type species N. heminoda from both sites, and N. subnoda from 13°N; Rhynchopelta , type species R. concentrica from both sites; Echinopelta , type species E. fistulosa from 21°N; Hirtopelta , type specics H. hirta from 13°N. These limpets are associated with the Pompei worm Alvinella , except for Rhynchopelta, which is associated with the vestimentifcran worm Riftia .     

The ultraviolet light and photosensitized inactivation of tobacco mosaic virus

The quantum yield for the inactivation of tobacco mosaic virus has been determined at 253.7 mµ and found to be 4.3 x 10^–6. The possible significance of the observed one-hit process of inactivation has been discussed in terms of the kinetics and the rupture of model substances including nucleic acid. The ultraviolet light inactivation, which proceeds independent of oxygen, occurs without change in physicochemical properties, with the possible exception of an enhanced sensitivity to thermal denaturation. The photosensitized inactivation of virus by acriflavine has been found to proceed parallel with the destruction of the dye. The action was found to be dependent upon adsorbed dye, and the inactivation is enhanced by the presence of oxygen.