Article II.-THE PENAEIDEA OF LOUISIANA WITH A DISCUSSION OF THEIR WORLD RELATIONSHIPS'

During two years of exploration of the coastal waters of Louisiana, 1929 to 1931, nine species of Penaeidae and six of Sergestidae were cap-tured. Of the Penaeidae, one (Solenocera vioscai) has not been pre-viously described, and two others, Parapenaeus longirostris (Lucas) and Trachypeneus similis (Smith), are additions to the five that have been reported from the region by previous workers. These five species, Penaeus setiferus (Linnaeus), Penaeus brasiliensis Latreille, Trachy-peneus constrictus (Stimpson) (which is here replaced by a valid record, since the former one refers to T. similis), Xiphopeneus kroyeri (Heller), and Eusicyonia dorsalis (Kingsley), are represented in the material to be discussed. The ninth species taken is an aristaeine mysis, probably Gennadas elegans (Smith) which occurred in the open gulf outside of the strictly littoral zone. Of the six Sergestidae, only two (Acetes carolinae Hansen and Lucifer faxoni Borradaile) were found within the littoral area. Preadults of fou