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 longicornis (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 antennae,' 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 squatnifera (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 Perlustration 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 



^ Nordseefahrt der Pommerania, p. 292. * Vol. iii. p. 242, 1875. 



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