The Cardiac Notch in Decapods

The 1899 description and discussion by Henri Coutiere of the cardiac notch on the posterior margin of the carapace in certain decapods is translated and reviewed, with special emphasis on the alpheids, in which it is usually present, and the otherwise similar hippolytids, in which it is almost invariably absent. The genus Yagerocaris Kensley, 1988, is transferred from the hippolytids to the alpheids. Similar notches in other decapod families are deemed not to be homologous, even though the practical importance of the structures described by Coutière continues to defy explanation.