Corystes

Abstract: Having been favoured by Messrs. C.J.A. Meyer and Caleb Evans with the opportunity of examining three new Crustaceans recently obtained by them from the Lower Tertiary Deposits exposed during the excavations for the “Dockyard Extension Works” in Portsmouth Harbour, I beg to submit the following notes thereon. I. Family Corystidae. (Genus Palaeocorystes , Bell.) This family, represented at the present day by the genus Corystes common on our own coast, and in the Chalk, Greensand, and Gault by the genera Palaeocorystes and Eucorystes , has now been discovered in the Lower Eocene, at Portsmouth, by Mr. Caleb Evans, F.G.S. The specimen (see Plate IV., figs. 1 a, b), although far from perfect, is sufficient to indicate at once the genus to which it belongs, namely Palaeocorystes , and also that it is specifically distinct from those occurring in the Cretaceous rocks, already described by Prof. Bell and others*. The carapace measures one inch in length; but (both its anterior and posterior borders having been injured) it was, originally, probably nearly one-fourth of an inch longer. In breadth it measures 10 lines. Some portion of the anterior (orbital and suborbital) border can still be traced out; but the rostrum is quite destroyed. The surface of the carapace is smooth and devoid of ornamentation, save a few widely scattered and very minute puncta ; but where the delicate cortical layer has been removed, the carapace presents a finely granular structure. The two sigmoid markings, observable on the carapaces of all the Corystidae are also clearly

Abstract: [Le crabe Corystes cassivelaunus a ete eleve en laboratoire depuis l'oeuf jusqu'au stade megalope. Les cinq stades zoe et le megalope sont decrits et compares aux descriptions precedentes, fondees sur du materiel provenant du plancton., Le crabe Corystes cassivelaunus a ete eleve en laboratoire depuis l'oeuf jusqu'au stade megalope. Les cinq stades zoe et le megalope sont decrits et compares aux descriptions precedentes, fondees sur du materiel provenant du plancton.]

Abstract: During an investigation into the occurrence of various crab species in the Oban (West of Scotland) area, Iphitime cuenoti was found infesting the branchial cavity of Liocarcinus puber, L. corrugatus, L. depurator, Carcinus mamas, Cancer pagurus, Hyas araneus and Macropodia longirostris caught within, or on the sandy mud below, the Laminaria forest. The same crab species obtained from sandy habitats, and crabs peculiar to such a habitat (Portumnus latipes, Liocarcinus holsatus and Corystes cassivelaunus) did not harbour the polychaetes. Three or more worms were commonly found in each Liocarcinus host, the highest number recorded, in L. puber, comprising 9 adult and at least 98 juveniles, the latter being found between the gill lamellae. Over 90% of both L. puber and L. corrugatus were infested, 35% of L. depuratot, but less than 10% of any of the other species. The largest worms (up to 80 mm alcohol-preserved length) were found in L. puber and L. corrugatus. Worms were found to have either simple ...