CRUSTACEA. 



63 



Xantho tuberculata — R. Q. Couch, Bells Brit. Stalk-eyed 

 Crust., appendix p. 359. 

 This species, which was first described by Mr. Bell in his book, 

 on the British Crustacea, was added to our Fauna by the late Mr. 

 P. Q. Couch, of Penzance, son of the author of the first edition of 

 this report. 



Mr. Couch says that it appears to prefer deeper water than the 

 other two species, as he found it repeatedly in crevices of Eschar a 

 foliacea in the deep water off the Bunnell Stone, in Mount's Bay. 

 In the summer it approaches the shore and is found under 

 stones. It spawns in June. Mr. Bell adds "the name tuberculata 

 has been given to the species by its discoverer, from whom and 

 from his father, Mr. Jonathan Couch of Polperro, I have had so 

 many claims upon my acknowledgments for their intelligent 

 and ready assistance in the progress of the present work." 



Genus, Cancer. — Lin., Leach, Bell. 

 ,, Platycarcinus. — Edivards, Couch. 

 Carapace approaching to a transverse oval without furrows. 

 Cancer pagurus. — Edible Crab. — Linn., Leach, and Bell Brit. 



Stalk-Eyed Crust., p. 59. 

 Platycarcinus pagurus. — Edwards, Hist, des Crust., t. I, p. 413; 



Couch, Cornish Fauna, p. 68, 1838. 

 This is the species so highly esteemed for the table, and for 

 which a regular fishery is carried on. The male, called the Stool 

 crab, is much the larger, not uncommonly weighing a dozen 

 pounds, whilst the female, termed the Bon crab, is rarely half 

 that size. Although this crab is somewhat affected by cold 

 weather, so that it is most abundantly caught in summer, its 

 activity is not diminished by it, and some may be obtained at all 

 seasons. The fishery, therefore, is more influenced by the danger 

 to which the pots set to take them are exposed in stormy weather, 

 than by the absolute scarcity of the crabs. The haunts are along 

 the edges of the rocks, in situations varying from low water mark 

 to about 20 fathoms, and the selection is perhaps as much influ- 

 enced by the facility of hiding or burrowing, as by the supply 

 of food. The Bon crab begins to breed when about three inches 

 across the carapace ; and the spawn after remaining long attach- 

 ed to the parent, is buried beneath some shelter at all seasons of 

 the year; but when engaged in this duty the female feeds 



