ABSTRACT Professor Dahl purports to overthrow the long-standing premise that the primitive malacostracan carapace extends freely from the back of the cephalon. If the premise were overthrown, a number of serious difficulties would develop in long accepted hypotheses concerned with evolution within the Malacostraca as well as with the affinities of malacostracans with other crustacean taxa. However, we reaffirm that the free carapace is cephalic in the most primitive of the living malacostracans, the leptostracan phyllocarids, and in the ontogeny of the eucarids having the most anamorphic development known to the malacostracans, the Dendrobranchiata. These facts allow the formulation of hypotheses concerning (1) the loss of the carapace without the necessity of "resegmentation" in various malacostracans, and (2) the origin of the Maxillopoda from a malacostracan-like ancestor.