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 CRUSTACEANS the pleon, spikes on the rostrum, spikes all over the carapace and most of the legs, and yet its armature, which has earned it the alternative name of the ' devil crab,' does not prevent its being swallowed by the cod. In a dorsal view it might be taken for a crab in reality, but the pleon tells a different tale. In the female this part is greatly expanded, far more so indeed than in crabs proper, but the intrinsic anomaly of it is that the segments following the second are not simple, and, what is more, they are not symmetrical. The disconnected crustaceous pieces in the leathery skin on one side are much larger than those on the other. The want of symmetry brings to mind the tail part of the hermit-crabs, and it is from their type that Lithodes is supposed to have descended, with re-modification of the tail, to suit its altered conditions of life, when the piratical seizure of mollusc shells was dispensed with. To one other anomaly attention should be directed. This species, which belongs to the decapods, or ten-footed Crustacea, looks as if it had only eight legs. The truth is that, as in almost all the Anomala, the last pair are very small ; but besides this they are here tucked away out of sight beneath the margin of the carapace. In this situation they do not need, or rather they do need not, to be spiky, and they are not. Strangely contrasting in size with the preceding is the little Por- cellana longkornis (Linn.), with a carapace not a quarter of an inch long or broad. It represents a different division of the Anomala, in which the pleon is symmetrical and closely folded under the body in a crab-like fashion, but it is comparatively broad, and ends in a way not found in the Brachyura, though familiar in the Macrura. On each side of the seventh segment or telson are the two-bladed appendages of the sixth segment, these five plates together forming a fan, which in many genera constitutes a powerful swimming organ. As the generic name implies, this ' minute porcelain crab ' has a smooth carapace. Its specific name declaring that it has ' long antennas,' also by that fact is suggestive of its not being a true crab. It is reported by Metzger from the Norfolk coast at a depth of twelve to twenty-five fathoms.^ It is very common. From the same locality, at a depth of twelve fathoms, Metzger records Galathea squamifera (Leach),' the scaly galathea. In the division to which this belongs there is the swimming fan at the end of the pleon, but that pleon is not closely adpressed to the trunk and is developed more after the style of lobsters and crawfishes. In his Per lustration of Great Yarmouth Mr. Palmer makes the fol- lowing remarks : 'In July, 1873, two specimens of the crab {Limulus Longa Spina) were brought in by a fishing smack. The Malays use the long spines of these crabs as tips to their lances and arrows. Shrimps, the least but most delicious of all shell-fish, abound at Yarmouth, and are caught in large quantities during the summer months, giving employment to many industrious men.'* Limulus longispina (Van der Hoeven) is a native of Japanese waters, and should not lightly be included in the fauna of Norfolk, even if the fishing-smack obtained the specimens so named alive 187
 * Nordseefahrt der Pommeranta, p. 292. * Vol. iii. p. 242, 1875.