THE COMMON SHOKE CRAB 65 



front is horizontal, broad, lamellate, and projects over the 

 antennules and bases of the antemia35 which are widely 

 excluded from the orbits.' 



The genera are Trapezia^ Latreille, 1825, Tetralia, 

 Dana, 1851, and Qiiadrella, Dana, 1851, names indicative 

 of the prevailing shape. The species in general are small 

 and confined to the warm seas. According to the Russian 

 writer, Paulson, 1875, the lower antenna3 of Tetralia re- 

 quire that the last clause of the above-quoted definition 

 should 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 PortunidEe include about half as many genera as 

 the Cancridse. 



Carcinns, Leach, 1813, has the seventh joint of the 

 fifth legs narrowdy 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 Grab ; its extremely vivacious movements and its 

 reckless audacity when brought to bay j ustify its scientific 

 title and the corresponding French name for it of Grahe 

 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 

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

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



