44 DTTBLIN NATUEAL HI8T0EY SOCIETY. 



Xantho rivulosa, — I find I was in error in stating this crab had not 

 occurred to M'Calla. At least, a card has lately turned up in the Koyal 

 Dublin Society's collection, labelled ** Xantho florida, Roundstone," 

 which was most probably part of the collection purchased from M'Calla; 

 on this, undistinguished by any mark from numerous specimens of X. 

 fiorida, is a line male specimt^n of X rivulosa, which must have escaped 

 M'Calla's notice. It would then appear to be generally distributed 

 along the south and western coast. 



HookHead (E.B.)— Valentia Island, Galway Bay (A. G.M.), Eound- 

 BtoncBay (W. M'C), Portrush (0. C.) 



Portunm marmoreus. — Galway, Roundstone (W. M'C.) 



Ehalia Bryerii. — ^Belfast (0. C), Galway (A. G. M.), Roundstone 

 (W.M'C.) 



Ebalia Cranchii. — Belfast (0. C), Portmamock, Co. DubHn, q. v. 

 (R. Ball), Roundstone Bay (W.T.) 



Thia polita. 



I had the pleasure of seeing this crab dug out of its sandy home, 

 Professor Melville having kindly accompanied me to the station where, 

 in 1850, he first met the species, — a fine female specimen, that now 

 before your Society, was the only one met with. It bore the journey to 

 Dublin in a small tin box packed in wet sand remarkably well, and has 

 since been kept in a small vivarium.* 



This crab has given rise to some discussion as to whom the priority 

 of its discovery in Ireland is due. Having been lately looking over the 

 back Transactions of this and other Societies, I find myself in a position 

 to clear up much of the mystery of this " knotty" point. I hope, there- 

 fore, it will not be considered to be trifling with the time of the Society 

 if I lay before them the results of these investigations. 



Thia polita was first detected by that indefatigable collector, "W. 

 M'Calla, in Roundstone, in 1845 ; he failed in identifying it, as the fol- 

 lowing extract from a paper read by Dr. Charles Tarran before your 

 Society, January, 1845, proves : — 



** This winter I have added two species, Portunus marmorem, I have 

 not been able to determine the genus of the other: one thing is certain, 

 it is new to Britain, if not to science. The undetermined species was 

 found in shallow water, at extreme low water-mark ; I obtained five 

 specimens. Having paid considerable attention to the Crustacea, I had 

 no hesitation in writing to Dr. Scouler that I had been so fortunate 

 as to have added a new genus to this department." — Saunders^ News- 

 letter, January 9, 1845. ( Vide also Report of Dublin Natural History 

 Society for 1844-45, p. 17.) 



The species was subsequently identified, and published by Pro- 

 fessor Scouler, in a paper laid before this Society in January, 1846, 

 as the following shows : — ** Dr. Scouler then brought forward the dis- 



• StiU alivo and healthy, although now three months in confinement — June 28, 

 1857. 



