CRUSTACEA. 165 



Portunus marmoreus, Leach ; Bell, op. cit. p. 105. 

 On the West Sands after storms. Rather rare. 



Portunus holsatus, Fab. ; Bell, op. cit. p. 109. 

 Not uncommon in the stomachs of cod and haddock, Saccu- 

 lina occurs on this species occasionally (Plate IX. figs. 14 & 15). 



Portunus pusillus, Leach ; Bell, o]}. cit. p. 112. 

 Occasionally from deep water, and rather common in the 

 stomachs of the haddock and flounder. 



Genus PoRTUMNUs, Leach. 

 Portumnus variegatus^ Leach ; Bell, op. cit. p. 85. 

 Abundant on the sandy ground oft' the "West Sands. 



Genus Carcinus, Leach. 

 Carcinus nuenas, L. ; Bell, op. cit. p. 76. 

 [Plate V. figs. 7 & 8, and Plate IX. figs. 10-1.3.] 



Everywhere abundant between tide-marks and in the 

 laminarian region. Occasionally used as bait. Swarms in 

 the zoea-stage occur in autumn at tlie surface of the water in 

 the bay ; they are almost invisible with the exception of the 

 greenish-blue eyes. 



This crustacean has nine branchite : — the first rudimentary, 

 and attached to the horizontal portion of the first pair of 

 foot-jaws (Plate V. fig. 7) ; the succeeding, rather long and 

 delicate organs, fixed to the second pair of foot-jaws on 

 opposite sides of the horizontal portion ; while six are at- 

 tached to the body of the animal (four being prominent) 

 as in allied forms. The flabellum of the first pair passes 

 between the four prominent and larger branchiae and the 

 apodematous region, so as to sweep their inner surface; 

 while the organ of the second pair goes between the 

 same portion of the shell and the fifth and sixth branchiae 

 (counting from behind), and may also affect the exposed 

 surface of the seventh, which lies in the groove anteriorly. 

 The long and finely curved flabellum of the third pair of 

 foot-jaws curves externally, so as to brush all tlie seven. 



