THE AMERICAN LADY-CRAB 67 



last joint of the fifth legs lanceolate. The British species 

 which Bell names Portummi* variegatus^ Leach, he ought 

 in accordance with the rules of priority to have called 

 Portumnus latipes (Pennant). In distinguishing Por- 

 tumnus from the closely allied Platyonichus, Latreille. 

 1818, Bell or his printer has made a confusing mistake 

 by attributing to Plafyonich/us the acutely lanceolate ter- 

 minal joint in the fifth pair of legs, and the broad oval, 

 very much rounded joint to Portumnus, instead of putting 

 the contrast the other way round (see Plate II.). He men- 

 tions that in Portumnus, as in many other Portunidse, the- 

 pleon of the male is five-jointed, whereas in Plafyonichus- 

 it is seven -jointed. Unfortunately this distinction, which 

 would have been so convenient, only applies to two out of 

 the three species which are now allotted to the latter genus, 

 namely to Platyoniclius bipustulatus, Milne-Edwards, and 

 to Platyoniclius iridescens, Miers, a species in which the legs- 

 are said to be beautifully iridescent. 



Platyoniclius ocellatus was first described in 1799 by 

 Herbst, who records its habitat in the words, ' Das Yater- 

 laiid ist Long-Eiland bey Newyorck.' Both New 

 York and the ' Lady Crab ' of America have come to be 

 better known than they were in the time of Herbst. 

 Yen-ill and Smith, in their valuable report on the inverte- 

 brate animals of Yineyard Sound, give a figure of the crab 

 and many interesting particulars. It is, they say, perfectly 

 at home among the loose sands at low-water mark, and 

 also abundant on sandy bottoms off shore. It is a rapid 

 swimmer, and was not unfrequently taken on the surface- 

 of the sea. ' When living at low-water mark on the- 

 sand beaches it generally buries itself up to its eyes and 

 antennae in the sand, watching for prey or on the look-out 

 for enemies. If disturbed, it quickly glides backward and 

 downward into the sand, and disappears instantly. This 

 power of quickly burrowing deeply into the sand it pos- 

 sesses in common with all the other marine animals of 

 every class which inhabit the exposed beaches of loose 

 sand, for upon this habit their very existence depends 

 during storms. By burying themselves sufficiently deep 



F 2 



