40 2 Proceedings of the Royal Irish Academy. 



Intermediate between these two groups are three species, absent from the 

 Mediterranean, Anapagurus hyndmanni, Philocluras echinulatus, and Philo- 

 cheras bispinosa-s, of which the distribution seems at present to be centred in 

 the British Isles. 



The large excess of southern over northern forms is, perhaps, to be 

 expected, when it is realized that the west coast of Ireland lies in the track 

 of a current of warm Atlantic water, reinforced by an outflow from the Medi- 

 terranean, which sets northwards along the west coast of Europe, and produces 

 a marked effect as far north as the mouth of the White Sea. Such a current 

 would prove a formidable obstacle to the southern extension of northern forms, 

 both on account of its climatic effect and also by reason of the mechanical 

 obstacle which it opposes to the drift of floating larvae. 



It is, perhaps, worth noting that, of the forty-eight species which extend 

 their range into the Mediterranean, at least thirty-two are found in the 

 Adriatic, an area the fauna of which seems in many ways to resemble that of 

 the west coast of Europe. 



The majority of the species recorded are widely distributed forms, as is to 

 be expected ; perhaps the most interesting record in the list is that of Eupa- 

 gurus pubescehs, a northern species not found hitherto on the west coast of 

 Ireland, though known from the north coast. 



LIST OF SPECIES. 



Sub-order DECAPODA NATANTIA. 

 Pandalus montaspii Leach. — Clare I. harbour, one (W. P.). Scarce outside 

 the islands, Clew Bay ; Inishgowla, common (S. W. K.). 



Distribution. — From the extreme north of Norway to the English 

 Channel, N. E. America, Greenland, Iceland. Common round the British 

 and Irish coasts. 

 Pandalina brevirostris (Rathke). — Inishlyre, two; Inishgowla, few (S. W. K.). 

 Distribution. — From the extreme north of Norway to the Mediterranean, 

 the Adriatic. Common round the British and Irish coasts. 

 Hippolyte varians (Leach). — Clew Bay, moderately common (W. P.), Inish- 

 gowla, abundant (S. W. K.). 



Distribution. — From the extreme north of Norway to the Mediterranean, 

 the Adriatic. Abundant round the British and Irish coasts. 

 [Hippolyte prideauxiana Leach.] — Not yet recorded from Clew Bay, but pro- 

 bably occurs. It has been taken in Zostera beds in shallow water at 

 Ballynakill and Blacksod. 



Distribution. — Mediterranean, Bay of Biscay, Shetlands. West coasts 

 of Scotland and Ireland, English Channel. 



