200 



NATURAL HISTORY. 



and on the Irish coast. It is also met with in the Moray Firth, the Firth of Clyde, and in the 

 Channel Islands, where it is known as the Lady Crab, from its velvet coat. 



" An old male of the Velvet Fiddler is a striking and handsome Crab. His body generally is 

 clothed with a short velvety pile of a pale brown or drab hue, from beneath which here and there 

 shines out the glossy deep black shell, especially where rubbed, as at the edges. The feet, particularly 

 the plates of the oars, are conspicuously striped with black, the large and formidable claws are 



marked with bright scarlet and 

 azure, as are also the foot-jaws 

 and face, while the eyes are of 

 the richest vermilion, projecting 

 from hollow black sockets." 

 This species, when apprehensive 

 of assault, uses its powerful 

 claws " to strike transversely, as 

 a mower uses his scythe." 



Henslow's Swimming Crab 

 (Polybius henslowii), the only 

 known species of the genus 

 (Fig. 15), exhibits the natatory 

 structure to the greatest extent 

 of any British species. The 

 carapace even in the female is remarkably flat, and its form is nearly orbicular. The edge of the 

 carapace has five teeth on each side. The eyes are keen and active ; the chelse are exceedingly sharp- 

 edged. The four following pairs of limbs are all adapted for swimming. The colour is of a rich 

 reddish-brown. The texture of the whole shell is far lighter in density than any of the coast species 

 which live inshore. This is, in fact, a truly pelagic or open-sea Crustacean. The writer has seen 

 this Crab in large numbers swimming on the surface of the Bay of Biscay one hundred miles from 

 land ; and far off the coast of Cornwall the fishermen take them in the act of eating the Mackerel, 

 which they pursue and fasten on to with their knife-like nippers, 

 until the terrified fish becomes exhausted and is speedily van- 

 quished and devoured. 



A much larger species of Swimming Crab than the 

 British, named Portunus pelagicus, occurs in the seas of China 

 and Japan, and extends as far south as the Gulf of Carpen- 

 taria. It preys upon quite large fishes, and is "built," as 

 shippers would say, "for speed and lightness." Its habits were 

 well known to the Japanese, who have depicted this Crab most 

 accurately in one of their many wonderful picture-books, printed 

 from wood blocks, preserved in the British Museum. The 

 Portunus is represented in the very act of catching a live fish 

 many times larger than itself. These predaceous Swimming 

 Crabs are much disliked by the fishermen, because, when they 

 are taken in the nets with a haul of fish, they bite and mutilate all within their reach, as does the 

 Dog-fish and the other small Sharks common along the coast. 



Corystes casslvelaunus (Fig. 16). In this singular Crab the carapace is longer than it is broad. 

 The surface of the carapace is convex, and the regions somewhat distinctly marked by a groove sur- 

 rounding the heart, the intestinal and genital regions, forming altogether a remarkable resemblance 

 to the features of the human face, from which circumstance it has obtained the name of "the 

 Masked Crab." The sexes of this Crab differ so much in appearance that they have been described 

 as^ separate species. It is frequently to be obtained on the south and west coast of England and 

 Wales. The habit of this Crab is to lie buried in sand with only the antennae visible above the 

 surface. This is a very ancient type of Crustacean ; many representatives of it (Pcdceocorystes) occur 

 fossil in the Cretaceous beds (Gault and Greensand) of England. 



Fig. 15. HENSLOW'S SWIMMING CRAB. 

 (Polybius henslowii.) 



