102 THE ZOOLOGIST. 



uniform colour. The swimming blade in P. marmoreus is much 

 more elongated and pointed than either P. depurator or P. holsatus. 



The colour of the carapace is uniformly of a pale or yellowish 

 brown, marbled nearly over the whole surface with a tracing of 

 darker brown. A small patch, which is devoid of markings, 

 appears on either side immediately below the last spine of the 

 denticulation of the lateral anterior margin. 



This species is so closely allied to Portunus holsatus that 

 Bell remarks he is almost imperatively forced to consider them as 

 varieties of one species. Our experience, after carefully examining 

 living specimens, is that the points of difference between this and 

 P. holsatus are such as to establish its identity as a species. 



After long and careful collecting expeditions, extending over 

 many months, in the Channel Islands and the whole south coast 

 of England, Mr. Carrington's assistant, Mr. E. Matthews, only met 

 with this species in single examples near Guernsey and the Scilly 

 Islands, but near Falmouth he found about a dozen examples. 

 At the latter place it was so extremely local in its habitat that it 

 was only obtained by repeated dredging; in fact, the dredge 

 passed quite one hundred times over the one small bank covered 

 with Zostera where the specimens occurred ; and although the 

 immediate neighbourhood was even more carefully worked, none 

 were obtained elsewhere. Professor Bell notes that he obtained 

 nearly four hundred, of which three-fourths were females, at 

 Sandgate, in May, 1844, in two casts of the dredge. It is difficult 

 to doubt so close an observer as Bell, but knowing that P. holsatus 

 occurs on that coast in great profusion, we venture to think that 

 a mistake in the species recorded must have occurred. P. mar- 

 moreus has been recorded after storms at St. Andrews ; also from 

 Moray Frith and Roundstone, Connemara, Galway. 



Portunus holsatus, Fabr. 



This species, which, as we have already stated, seems to have 

 caused a considerable amount of difficulty in consequence of its 

 strong resemblance to P. marmoreus, is, nevertheless, decidedly 

 distinct ; this can be observed when several of each species are 

 seen together. 



The general appearance of the carapace is, that it is more 

 rounded and much smoother than that of the former species, 

 whilst the teeth occupying the space between the orbits are 



