I. '08. 102 



Irisli distribution. — Although hitherto unrecorded from 

 Irish waters, there can be little doubt that the species is far 

 from uncommon on the west coast. Specimens are extant in 

 the Dublin Museum from Belmullet, Co. Mayo, from Ventry 

 Harbour, Co. Kerry, and from Dunbeacon Harbour, Co. Cork. 

 Between 1899 and 1903 it was repeatedly found in Bofin and 

 Ballynakill Harbours, Co. Galway. 



H. prideauxiana has not yet been detected on the north 

 coast or in the Irish Sea. 



Vertical range.— On the Irish coast this species seems to 

 be exclusively littoral, but in the Adriatic it has occurred in 

 as much as 30 fathoms (Heller). 



Genus Spirontocaris, Spence Bate. 



Five species of this genus are known from British and Irish 

 waters, but two of them, S. Gaimardi and S. polaris, have not 

 60 far been met with off the Irish coast. 



I. Rostrum long, reaching to at least three-quar- 

 ters the length of the antennal scale ; a 'supra- 

 orbital spine on carapace ; [carpus of second 

 pereiopod composed of seven segments], 



A . Rostrum very deep in side view ; antennular 



peduncle long, reaching to rather more than 

 half the length of the antennal scale ; an exo- 

 pod and epipod on the third maxillipede ; epi- 

 pods on first three pereiopods, . S. spina (p. 103). 



B. Rostrum not so deep in side view ; antennular 



peduncle short, not reaching to half the length 

 of the antennal scale ; an exopod and epipod 

 on the third maxillipede ; epipods on first two 

 pereiopods, . . . . S. Gaimardi (p. 103). 



C. Rostrum not so deep in side view ; antennular 



peduncle long, reaching to fully three-quar- 

 ters the length of the antennal scale ; an epi- 

 pod but no exopod on the third maxillipede ; 

 epipods on first two pereiopods, . S. poiaris (p. 103). 



II. Rostrum short, not reaching to one-third the 

 length of the antennal scale ; no supra-orbital 

 spine on carapace ; [an exopod and epipod on 

 third maxillipede]. 



A . Apex of rostrum bidentate ; epipods on first two 



pereiopods ; carpus of second pereiopod com- 

 posed of six segments, . . S. Cranchi (p. 106). 



B. Apex of rostrum simple, acuminate; epipods on 



first three pereiopods ; carpus of second pereio- 

 pod composed of seven segments, . S. pusiola (p. 107). 



