ORACH Vr III. 197 



Peculiar iin-iil. -nt* arc concomitant on prolonged repose: it admit* 

 encroachments on tin- Mate of the living animal, incompatible with vital 

 sensation- : and. first of all. it allows numerous parasite* to found a iinlu- 

 amid.-t li\ in:.' matter, ami themselves to live at the expense of life ; now 

 tin- wlm! IMC with tin- limb* and other accessories large and small, 



becomes invested by foreign matter, completely disguising, even dis- 

 t nrtiii:: tlii- true form and appearance of the spec-mien and all it* parts, 

 from those the most familiar with them. 



Hut thin is greatly promoted by the situation of both the subject and 

 the par.uMte. Thus, some escape it entirely, and the shell remains as free 

 and clean of all parasite substances and foreign matter, and of as vivid 

 colour, as if carefully cleansed of accidental impurities. 



Such specimens, however, are not numerous, their condition pro- 

 bably involving more peculiarities than we are commonly aware of. 



One is represented, Plate XLV1II. fig. 1, the length of the body 

 about an inch and a half, its breadth about an inch. Claws rather long 

 and slender, as are the limbs, which, armed with nails, expand five 

 inches between the opposite extremities. The rostrum is cleft, and the 

 eyes seated on peduncles, standing at a large angle to the axis of the 

 body ; which is owing to contraction of the breadth : the shell of some 

 is more irregularly triangular than that of any of either of the preceding. 

 Ite colour is universally tile red. 



The apron of the male tends to an irregular quadrangular form ; 

 that of the female, of larger dimensions, is directed to protection of the 

 spawn, which is a close compact mass in its earlier stages. Then it is 

 vivid red, but becomes pale as advancing towards maturity, for the skin 

 of the capsules growing thinner with age, its consistence relaxes, and in 

 July, when in great perfection, cluster*, like bunches of currant*, maybe 

 separated ; but they are intricate, nor easily divided, so as to be distinctly 

 seen and represented. Plate XLIX. figs. 4. 



Some years ago a fine small specimen. Plat.- XLIX. fig. 6, was washed 

 on board a steam vessel plying btt\\nu Orkney and Shetland, during a 

 storm ; on reaching me this creature fed voraciou>]\ on most animal 

 substances. 



