• In our description of the sea urchin depicted in Aperture (9 June, p 26) we wrongly described it as expelling its guts through its mouth. In fact, the animal was captured as it defecated.
• New York lawyer Maura Grossman’s co-author on the study assessing new software for sifting legal documents (23 June, p 22) was Gordon Cormack of the University of Waterloo in Ontario, Canada.
