DUBLIN NATITKAL HISTORY SOCIETY, 101 



southern, western, and north-eastern coasts, though little attention 

 seems to have been paid to its habits. It is much rarer than the last, 

 and certainly much more solitary. I never met more than a pair toge- 

 ther, whilst of Xantho florida twelve or fourteen frequently occur under 

 a single stone. It is also more active, and does not feign death to as 

 great an extent ; it also frequents much wetter places in sandy pools, 

 and is found lower down on the tidal zone. Several specimens I found 

 were carrying their spawn, which was of a bright scarlet colour. Spe- 

 cimens occurred of every size, as the series before the meeting shows ; 

 but it does not appear to attain as large a size in this zone as X. florida. 

 There is a greater variety in colour ; the ground-colour in all is yellow, 

 more or less light ; this in some specimens is prettily mottled or dotted 

 with red; in others, patched and blotched with the same colour; it cannot 

 be looked on as a common crab ; I should add, it lives well in the aqua- 

 rium. Both species are manifestly scavengers. 



P. tetraodon (the four-horned spider crab) next claims our attention, 

 first added to the Irish list by M'Calla. It has not yet been, I believe, 

 recorded south of Galway Bay. We met it very abundantly, and always 

 in the one habitat, the branching stems of that pretty alga, Gelidium 

 corneum, in shallow rock pools. The first specimen was detected by 

 Mr. Foot, but subsequent research showed us that every plant of this 

 species swarmed with it. All the specimens were young, being under 

 an inch in length. I have no doubt it occurs all along the south-west 

 coast, and has been mistaken for Hyas, which it much resembles. 



The Corwich, which should come in here, only occurred to me once, 

 dead, and therefore may be passed by. 



Of Crustacea also occurring on the east coast, the first is that pretty 

 little species, Athanas nitescens. This species, though not common, is 

 by no means rare under stones. It is a regular little miniature craw- 

 fish. Its mode of swimming is very characteristic, as it preserves a 

 straightforward path, its disproportioned claws outstretched in front of 

 the body, and the tail expanded, its progress slightly undulating, and 

 its motion communicated to it by flapping the outer plates of the tail. 

 There was little variety in colour, which was deep vinous olive, with 

 dots of red, the tail occasionally darker, and sometimes, though rarely, 

 barred with white. It appears at Lahinch to replace the Hippolytes in 

 Dublin. This species has only occurred once to me in Dublin. 



Pilumnus hirteUus occurs, but not nearly as numerously as in Dublin. 

 The specimens were all small, and confined to the laminarian zone. 



The hairy broad-claw, Porcellana platycheles occurs more generally, 

 and in much larger numbers, than in Dublin. It appears to replace to 

 a great extent its congener, P. longicornis. 



This latter species is far from common, being much rarer than in 

 Dublin. 



The scaly Spanish lobster {Galathea squamifera) is very common, 

 and universally diffused. I met one or two varieties of it. 



The common prawn {P. serratus) is extremely common on the muddy 

 r 



