Erratum.
In the report "Associative behavioral modification in Hermissenda: Cellular correlates" by T. J. Crow and D. L. Alkon (18 July, p. 412), the last sentence on page 412, column 2, paragraph 1, should read, "We have now found that modification of the photopositive response in Hermissenda is correlated with cellular changes in the type B photo-receptors."