THE COMMON SHORE CEAB 65 



front is -rizou ,al, broad, lamellate, and projects over the 

 antennuies and bases of the antennas, which are widely 

 excluded from the orbit's.' 



The genera are Trapezia, Latreille, 1825, Tetralia, 



Dana, 1851, and Quadrella, Dana, 1851, names indicative 



of the prevailing shape. The species in general are small 



pnd confined to the warm seas. According to the Russian 



'ter, Paulson, 1875, the lower antennas of Tetralia re- 



that the last clause of the above-quoted definition 



\ be cancelled. 



Family 3. Portunidce. 



The carapace is depressed, moderately transverse, and 

 usually widest at the last antero-lateral marginal spine. 

 The 'front' is horizontal and not spatuliform (see p. 71). 

 The orbits and eye- stalks are of moderate length. The 

 spine or tooth at the outer angle of the orbit does not 

 project laterally beyond the teeth of the antero-lateral 

 margin, of which more than one, usually from five to nine, 

 are developed. The last legs of the trunk are commonly 

 adapted for swimming, with the seventh joint ovate, flatly 

 expanded. 



The Portunidas include about half as many genera as 

 the Cancridas. 



Oa/rcw/uSj Leach, 1813, has the seventh joint of the 

 fifth legs narrowly lanceolate. The species Carcinus mcenas 

 (Pennant) is the most obtrusive of all the British Brachyura. 

 Its numbers justify its English designation as the Common 

 Shore Crab ; its extremely vivacious movements and its 

 reckless audacity when brought to bay justify its scientific 

 title and the corresponding French name for it of Grdbe 

 enrage. In the early part of this century Leach stated that 

 it was sent to London in immense quantities and eaten by 

 the poor. Professor Stalio says that at the present day 

 it is a considerable source of food-supply to the humbler 

 classes on the shores of the Adriatic, that in the soft state, 

 just after the shedding of the skin, it is welcome at the 

 tables of the rich, and that the Istrian fishermen pound it 

 up and use it as a most attractive bait to the sardines. On 



F 



