10 DUBLIN NATURAL HI8T0ET SOCIETY. 



vierian Society in 1849. These two latter are referred to as J. V. T. 

 and C. C. S. My o^^^l notes are, in every case, unmarked, the locality 

 being given without any initial. 



For the west, in addition to my own notes made at Yalentia Island, 

 in 1856, and at Kilkee, Galway, &c., in 1852, I have also made use of 

 a catalogue, supplied me some years since through the kindness of Dr. 

 Farran, of the principal species captured by W. M'Calla in Birterbie 

 and Roundstone Bays, marked by the initials W. M'C. 



Correcting and adding to all these various sources from Bell's Bri- 

 tish Crustacea, and William Thompson's Notes on the subject, as given 

 posthumously to the world in the fourth volume of the ''Natural History 

 of Ireland." This last has been noticed as W. T. 



The list by no means purports to be a complete distributional one ; 

 a task so comprehensive must be left for the future; but is merely 

 intended to notice such species as either came directly under my own 

 observation while living, or of which specimens, concerning whose au- 

 thenticity there could be no doubt, were seen by me. 



So much has lately, that is to say, within the last few years, been 

 said and printed concerning the superior capabilities of the west of Ire- 

 land as a field for research, that naturalists have been insensibly led to 

 look on it as the El Dorado of Irish Natural History, where " monster 

 nuggets," in the shape of new species, and rare animals and plants, are 

 tossed up by every tide and breeze ; the usual answer of the old hands 

 and authorities to the anxious inquirer seeking information regarding 

 the locale of some rare species *' Common in the west," helping to foster 

 this opinion, so that every naturalist could not but feel impatient for an 

 opportunity to examine into and revel amidst such treasures. Any one 

 who has felt the pleasure of breaking ground in a comparatively new 

 and seemingly rich field can quite appreciate the feelings with which 

 I gladly accepted an invitation to spend a few weeks at Valentia Island, 

 which, embayed as it is in an inlet of the Co. Kerry, ought to furnish 

 the carcinologist with every species which frequents the coast. 



Among the many species marked as Irish, on the authority of the 

 occurrence of a single specimen, none, with, perhaps, the exception of 

 Polijhiu8 Henslowii, possess more interest than the subject of this notice, 

 Xantho rtvulosa, one of the types of a genus which, essentially subtro- 

 pical, reaches its northern limit on the British shores, itself an un- 

 doubted member of that Fauna whose scattered members, in characters 

 not to be mistaken, attest the probability, nay, almost the certainty, of 

 the truth of one of the most brilliant theories ever propounded, — that 

 of the lamented Edward Forbes, — surmising the union and inter- 

 mingling, at some period of the world's history, of the Fauna of the 

 west of Ireland and Mediterranean districts ; add to this the fact of its 

 having been detected hitherto in Ireland only at the extreme north, and 

 that, when then discovered, now fifteen years back, a second specimen 

 was sought in vain ; that during this long interval it has remained un- 

 detected, escaping the careful research of even "W. M'Calla (at least, it 

 neither appears among his lists, nor can I find specimens of it in the 



