Copepoda taken in the West of Ireland. 139 



branch quite rudimentary. Cletodes, however, has the first 

 pair of antennas six-jointed, the second antennas without a 

 supplementary branch, and the four pairs of swimming-feet 

 all alike, the inner branch ending in two long filaments. 

 Under these circumstances we propose to call Claus's genus 

 Lilljeborgia by the new name Orthopsyllus. 



Genus Poecellidium, Claus. 



1. Porcellidium Jimbriaticm, Claus. 



?Sterope ovalis, Goodsir, Ann. & Mag. Nat. Hist. vol. xvi. (1845), pi. xi. 

 fig. 11. 



Dredged on a bottom of decaying vegetable mud in Bir- 

 tirbuy Bay, and on Laminarice in Clifden and Ventry 

 Bays. 



It seems to us most probable that Goodsir's figures and 

 description (loc. cit.) apply to this species, and not to Zaus 

 ovalis as supposed by Dr. Claus. If this could be ascertained 

 with certainty, Goodsir's nomenclature would have to be adopted 

 on the ground of priority. 



2. Porcellidium viride (Philippi). 



Thy one viridis, Phil. Arcfiiv fiir Naturg. 1840, p. 190, Taf. iv. fig. 2. 

 Porcellidium dentatum, Claus, Die frei-lebend. Copepod. (1863) p. 140, 



Taf. xxii. figs. 2-5 ; and Beitriige zur Kenntniss der Entom. (1860), 



Taf. ii. figs. 19-22. 



Dredged in Birtirbuy Bay in company with the preceding 

 species ; on weeds in Clifden, Westport, and Ventry Bays. 



There can be little doubt that Dr. Philippi's figure applies 

 to this species ; and we therefore adopt his specific name ; 

 but the generic term Thyone is preoccupied, having been 

 applied by Oken to a genus of Holothuriada?. 



3. Porcellidium subrotundum, Norman. 

 P. subrotundum, Norman, Last Shetland Dredging Report, p. 297. 



Dredged in Birtirbuy Bay with the foregoing ; also on the 

 fronds of Laminarioz in Clifden Bay. 



4. Porcellidium tenuicauda, Claus. 



P. tenuicauda, Claus, Beitrage zur Kenntniss der Entom. (1860), p. 6, 

 pi. ii. figs. 10-15 ; and Die frei-lebend. Copepod. p. 140. 



A few specimens taken from the interior of the " bulb " of 

 Laminaria hdbosa in Birtirbuy Bay ; also on weeds in Clifden 

 and Ventry Bays. Scarce. 



