Copepoda tahen in the West of Ireland. 127 



branch very short, about half the length of the outer branch, 

 the last joint of wliich is very long and truncate at the apex ; 

 marginal and terminal spines very small. The fifth feet in 

 both sexes are cylindrical and one-branched ; in the male four- 

 and in the female three-jointed, those of the femcde^ however, 

 being much shorter than those of the male, and having joints of 

 nearly equal length terminated by two or three fine short setse.. 

 In the male the first and fourth joints are much elongated, the 

 foot of one side being swollen, and bearing a long, slender, 

 curved process. Abdomen of female four-jointed (including 

 caudal segments), first joint equal in length to the second 

 and third. Caudal seta scarcely equal in length to the last 

 three segments. Length * yV of an inch. 



Taken plentifully in the open sea in several places off" 

 Ireland : ofi" the mouth of ihe Shannon ; Galway Bay ; off 

 Loup Head ; Dingle Bay ; near Valentia ; Rockall Bank ; 

 in lat. 51° 22' N., long. 12° 25' W., and lat. 53° 24' N., long. 

 15°24' W. 



Genus PsEUDOCALANUS, Boeck. 

 {Clausia, Boeck, 1864.) 



Pseudocalaniis elongatus, Boeck. 



Abundant in the open sea and in tide-pools. 



The generic term Clausia has been recently (1872) with- 

 drawn by M. Boeck, it having been previously applied by 

 Clapar^de to a genus of parasitic Copepoda. M. Boeck pro- 

 poses instead the name Pseudocalanus. 



Genus DiAS, Lilljeborg. 

 Bias longirenii's, Lilljeborg. 

 Abundant in the open sea and between tide-marks. 



Genus Temoea, Baird. 

 Temora longicornis (Miiller). 

 Occurring very abundantly in the open sea as well as in 

 tidal pools. 



Genus IsiAS, Boeck. 

 Isias clavipes, Boeck. 

 On the fronds of Laminar ice in Clifden and Roundstone 

 Bays. Rare. 



* The measurements are in all cases exclusive of the tail-setae. 



