14 DUBLIN NATUEAL HISTOET SOCIETY. 



Ocean, and even the habitat, — which appears to be erroneously given in 

 Bell as deep water, — at least in Valentia Island, I find P. arcuatus tole- 

 rably abundant under weed-covered stones, between tide-marks, pre- 

 cisely as Portunus itUegrifrons occurred to me in Port Philip Bay, 

 Australia. The young specimens of this species are, probably, often 

 passed over as Carcinus rmenas, from which it is often difficult to sepa- 

 rate them. It is, most probably, a southern species, that is to say, one 

 of Forbes's Atlantic types. 



In Ireland it has been recorded as occurring as follows : — Strangford 

 Lough (0. C), Portmamock, Co. Dublin (R. B.), Dublin Bay, 1852, 

 Cork (J.V.T.), Valentia Island, Killeries (W.T.). 



P&rtunu8 depurator occurs, but not common. This species has 

 been erroneously supposed to be rare in Ireland, probably from its being 

 generally an inhabitant of tolerably deep water : it is neither rare nor 

 yet local, as the following list shows : — 



Belfast (0. C), Portmarnock, Dublin, Bray, Youghal (E. B.), Va- 

 lentia, Dingle, (W. Andrews, Esq.), Roundstone (W. M'C), Galway. 



Portunus holsatus did not occur to me ; specimens of it were shown 

 me, and specimens from Dingle Bay, collected by Wm. Andrews, Esq., are 

 before you. This species is undoubtedly more northerly in its tendency 

 than the preceding; in Dublin Bay (where it is far the commonest spe- 

 cies) a wrinkled variety, hardly to be distinguished from P. depurator, 

 occurs especially in Dalkey Sound; it frequents sandy bottoms more 

 than that species. 



Distribution :— Belfast (W. T.), Dublin, Cork (J. V. T.), Dingle 

 (W. A.), Roundstone (W. M'C), Galway, 1857. 



Portunus pusillus occurs rare ; a generally diffused species ; but 

 seemingly rarest on the western shores. In Dublin Bay it occurs 

 commonly in the extreme laminarian zones, as at Dalkey Sound, 

 where, nearly in every haul of the dredge, specimens may be captured. 



Co. Down (O.C), Dublin, Cork (J. V. T.), Valentia, Roundstone 

 (W. M'C), Killeries (W. T.) 



The only other Portunus taken in Ireland (P. marmoreus) was, as 

 you have been already informed to-night, first captured by W. M'Calla, 

 in Roundstone Bay.* Into its history there is no necessity to go further, 



in a very minute^ obtuse tubercle. Upper edges of second, third, and fourth pair of legs 

 very sparsely hirsute ; fourth joint broadly keeled above ; fifth and sixth acutely 

 keeled; sixth joint slender, styliform ; terminal joint of posterior pair of legs nar- 

 nowly lanceolate, with a raised central line, hairy on the edges. 



The specimens obtained were all young. I hare, therefore, preferred inserting 

 the species in a note ; but it is probable it has been passed over as either P. arcuatus 

 or F. corrugatus. It might also be easily mistaken for young of G. mccnas. It occurred 

 in the rock-pools and also under stones on Ringlass Point. 



* The following are M'Calla's own words recording this discovery : — 



" PORTUNUS MARAIORKUS. 



" A short time previous to leaving Connemara, I had the pleasiire of finding a 

 single individual of this species. This is the first instance of its occurrence as Irish. 

 Habitat : a sandy beach, at extreme low water ; locahty, Island of Innislacken." — 

 Saunders's News-Letter, Jan. 9, 1845. 



