CRUSTACEANS 



female is the rule throughout the Malacostraca. Williamson points out 

 that Frank Buckland was mistaken in supposing that soft crabs always 

 contained a great deal of water, for ' the body fluid of the crab is not 

 water ; it is richly albuminous : on exposure to air for a little time it 

 becomes black ; and if a quantity of it is treated with picro-sulphuric 

 acid it coagulates into a solid mass.' ' 



In the family Cancridae to which the great eatable crab belongs is 

 placed a very different looking and somewhat anomalous form, Pirimela 

 denticulata (Montagu). Kent has the credit of having introduced this 

 pretty little species to science, though the honour of first naming it 

 belongs to the celebrated Devonshire naturalist. Montagu called it 

 Cancer denticulatus, and together with a characteristic figure supplied an 

 account of much merit considering the date at which it was com- 

 posed. He described it as follows : — ' Thorax broad before, narrow 

 behind, rugged with spines and tubercles, the margin continued in one 

 series of subserrated denticulations : the front between the eyes is quin- 

 quedentate, the middle spine the longest : the sides are also quinque- 

 dentate, besides a small process over each eye : eyes prominent : antennae 

 obscure ; the arms not longer than the body, angulated, or ridged 

 longitudinally with blunt spines at the top of the middle joint ; fangs 

 angulated and denticulated ; the legs are also angulated ; claws subulate : 

 tail narrow, regularly tapering. Length three-quarters of an inch, 

 breadth rather more. This singular species of crab was sent to me, 

 amongst a variety of British Cancri, by my late worthy friend Mr. Boys, 

 as the produce of the coast of Sandwich.' ^ It should be understood that 

 by the ' fangs ' are intended the thumb and finger of the chelipeds or 

 front legs, the middle joints of which are spoken of as ' arms.' The 

 subulate claws are the awl-shaped fingers or terminal joints of the walking 

 legs. It is to be lamented that Montagu only described two out of the 

 various ' Cancri ' which his friend sent him as products of this county. 

 Besides the extreme difference of size between the great C. pagurus and 

 the little Pirimela, it will be noticed that the former has each antero- 

 lateral border of the carapace divided into nine lobes, while in the latter 

 each, by a much more common arrangement, is cut into five teeth. In 

 the family which includes them both, the folding of the little first 

 antennae is longitudinal, but in the next two families it is transverse or 

 very oblique. 



Of the Xanthids one representative is reported from Dover, where, 

 it is said, Pilumnus \hirtellus (Linn.) may be found ' under stones below 

 Shakespere's and Abbot's Cliffs.' ' This is a hairy little species having 

 the ' front,' that is the border between the orbits, chiefly composed of 

 two broad finely denticulate lobes. Each antero-lateral margin of the 

 carapace has five teeth, but the tooth adjoining the orbit is very small. 



1 Fishery Board for Scotland, iSth Annual Report, pt. 3, 105. 



2 Trans. Linn. Soc. London, ix. 87, pi. 2, fig. 2 (paper read 1805, published 1808). 



3 Handbook to Dover, p. 87. As all the references to this useful guide will be concerned with pages 

 87, 88, this notice will perhaps suffice once for all. 



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