282 Mr. W. Thompson on the Crustacea of Ireland. 



Portunus depurator, Leach, Mai. pi. 9. f. 1 & 2. 



P. plicatus, Edw. Crust, t. i. p. 442. 



Cancer depurator, var.* Penn. vol. iv. p. 6. pi. 4. f. 2. 



From Templeton noting this crab merely as " found on the sands 

 at Dunfanaghy, co. Donegal, July 13, 1815," and from the specimen 

 named P. depurator in Mr. J. V. Thompson's collection (now in the 

 College of Surgeons, Dublin,) being in reality P. lividus, it might be 

 supposed that the species is not common. We have however dredged 

 it in Strangford lough, in the open sea off Down, and on the Con- 

 naught coast. Daring some weeks spent at Bangor, near the entrance 

 of Belfast bay, in the autumn of 1835, I found this to be the most 

 common species of crab thrown by the waves upon the beach — Care, 

 mcenas being the common one found alive between tide-marks. Mr. 

 R. Ball mentions that the P. depurator is local, but abundant where 

 it does occur about Youghal. 



Leach describes this species — " P. testa subcomplanata lineis ele- 

 vatis et transversis abbreviatis e granulis compositis," and Pennant 

 attributes to it (his " Cancer depurator, var.") a tuberculated surface. 

 What is just quoted from Leach applies admirably to all my speci- 

 mens, small and large — his figure shows the appearance tolerably 

 well. This author remarks, that it " is by far the most common spe- 

 cies [of Portunus] that inhabits the British coastf." 



Portunus lividus, Leach, Mai. pi. 9. f. 3 & 4. 

 P. holsatus, Edw. Crust, t. i. p. 443. 



Is not common. Templeton mentions it as found by him " on the 

 shore at Dunfanaghy." We have dredged it on more than one oc- 

 casion in Belfast bay, and have obtained it on the beach at Carn- 

 lough, county of Antrim. In Mr. R. Ball's collection are several 

 specimens which were dredged in Dublin bay. Leach mentions his 

 having seen but two examples of this species. 



Portunus corrugatus, Leach, Mai. pi. 7. f. 1 & 2 ; Edw. Crust, t. i. 

 p. 443. 

 The only specimens of this species which I have seen are some fine 

 examples from Larne andCarrickfergus in the Ordnance collection, and 

 a single specimen obtained on the Dublin coast by Mr. R. Ball. Mr. 

 J. V. Thompson notices P. corrugatus as inhabiting the harbour of 

 Cove, but those so named in his collection are the wrinkled variety of 

 P. depurator. 



* M. Edwards refers to Pennant's other figure of C. depurator with doubt, 

 as identical with P. rnarmoreus, Leach. 



f Portunus rnarmoreus, Leach, Mai. pi. 8 ; Edw. Crust, t. i. p. 442. 



Mr. J. V. Thompson observes that, " several species of Porttmus inhabit 

 the harbour of Cove, as depurator, arcuatus, corrugatus and marmoratus, of 

 which the last is perhaps the most common." Ent. Mag. vol. iii. p. 278. On 

 examining the specimens from Cork in that gentleman's collection, labelled 

 as P. marmoratus, I find that they are the P. pusillus of Leach. Of P. rnar- 

 moreus I have not yet seen any Irish examples. 



