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 CRUSTACEANS are united in the pleon of the female both of that and the remaining species, E. tumefacta. A. Milne- Edwards and Bouvier corroborate these statements in 1 900. Leach adds that in the last-named the pleon has the sixth and seventh segments united as well as the group from the third to the fifth. Pennant's Ebalia is further distinguished from the other two by the cruciform swelling on the carapace, and Cranch's from Montagu's by the more slender elongate 'arms' of the chelipeds. The Brachyura anomala or Dromiacea, unlike the genuine Brachyura, have a pair of appendages on the first pleon segment of the female. They make a late and scanty appearance in the Cornish fauna, for though a species of Dromia is figured and described in Leach's celebrated work, Malaco- straca Podophthalmata Britanniae, the figures on Plate XXIV, A, and the description of >. mediter- ranea, Leach, were added in 1875 by Mr. George Brettingham Sowerby, F.L.S., who writes: ' This very hirsute species frequently becomes covered with sponges, so that little of the shell is visible. Although long known as a Mediterranean crab, its existence in our seas has only been recently discovered. The figure is taken from a large specimen now in the British Museum, which was dredged off Penzance, and for some time lived captive in a tank.' Sowerby himself, however, gives a reference to the Zoological Journal (1825), vol. i, p. 419, which shows that John Edward Gray had noted the occurrence of this species on the English coast as early as 1824. The name Dromia mediterranea, Leach, quoted by Gray, was perhaps unaccompanied by any description, otherwise it would have preference over D. vulgarly Milne-Edwards. This western species agrees very nearly with the oriental D. rumphii (Fabricius), but is larger and has the carapace raised into bosses instead of being smooth, besides showing some differences in the lateral teeth. With the red fingers of the chelipeds and the two little hinder pairs of legs laid on the back, this great furry globose species makes an impressive object. It should be noted that in the family Dromiidae the gills are phyllobranchiae, fourteen to sixteen on each side, that the pleon is seven-segmented in both sexes, and that between its sixth and seventh segments there are two little lateral plates, which at least with some probability represent the appendages of the sixth segment that in the genuine Brachyura are always missing. The Macrura anomala are subdivided into Paguridea, Galatheidea, and Hippidea. With mem- bers of the first two divisions Cornish waters are rather liberally supplied, and as all our Pagurids have the abdomen or pleon very little calcified and more or less twisted to suit their borrowed habi- tations, they are easily distinguished from the Galatheids, in which the pleon is crustaceous and symmetrical. Both groups are distinguished from the Brachyura by the well-developed appendages of the sixth pleon segment. Among the very few notices of Cornish Crustacea which the eighteenth century supplies we have this observation by Borlase : ' Of the shrimp kind, great quantities are taken in Helford Harbour, Mount's Bay, etc. in calm weather. Here we often find the hermit-shrimp, bernard, or eancet/us, remarkable for taking possession of some empty shell, and there fixing his habitation as firmly as if it were his own native place ; when it marches, it draws the shell after it ; in danger retires wholly into it, and guards the mouth with one of its forcipated claws." A footnote says, 'Some have erroneously imagined that this was a young lobster I' 1 The knowledge was gradually acquired that ' hermit-shrimps ' are not all of the same species, but the Cornish Paguridae were all in the first instance referred to the one genus Pagurus of J. C. Fabricius, and even in 1878 this arrangement is retained by Spence Bate. They are, however, now distributed among several genera. Professor E. L. Bouvier has supplied the student with a useful clue to the intricacies of the family. 2 The genera Eupagurus (Brandt), Spiropagurus (Stimpson), and Anapagurus (Henderson), agree in having the third maxillipeds clearly separated at the base, and the right cheliped generally stronger than the left. But Pagurus (Fabricius), as now restricted, Diogenes (Dana), and Cakinus (Dana), have the third maxillipeds contiguous at the base, and the chelipeds generally subequal, or the left stronger than the right. In the first group Eupagurus has no salient point at the sexual orifices on the basal joint of the male's last thoracic legs, but Spiropagurus has such a process forming a tube long and spirally coiled, while Anapagurus has a simply curved tube, the tube in each case being situated on the basal joint of the left leg. In the second group, although the three genera agree in having no salient sexual appendages, Pagurus alone has horny tips or nails to the chelipeds, and Diogenes alone has a movable process on the ocular segment betwen the ophthalmic scales. In Eupagurus the three Cornish species are thus distinguished by Bouvier. E. cuanensis (W. Thompson) has the upper surface of the right chela very hairy and furnished with numerous sharp tubercles of which the strongest are grouped in longitudinal series, and the inner margin of this chela is straight, the outer much arched. In E. prideaux (Leach) and E. bernhardus (Linn.) the right chela has its upper surface scarcely at all hairy, but furnished with granules or numerous tubercles that are sometimes sharp, and both margins usually a little arched. In E. prideaux the granules or fine denticles are almost all equal, while in E. bernbardus the granules or denticles are rather strong and become 1 The Nat. Hist. ofCornto. (1758) by William Borlase, A.M., F.R.S., Rector of Sudgran, p. 274. ' La Feuille des Jeunes Naturalistes (1886), ser. iii, 26 Annee, No. 308. i 265 34