126 Messrs. Brady and Robertson on Marine 



XVIII. — Contributions to the Study of the Entomostraca. 

 By George Stewaedson Beady, C.M.Z.S., and David 

 Robeetson, F.G.S. 



No. VIII. On Marine Copepoda taken in the West of Ireland. 



[Plates VIII. & IX.] 



The following notes embrace the chief results of our worl 

 amongst the marine Copepoda during three visits to the coasts 

 of Galway and Mayo. Had these little creatures been the 

 primary object of attention, the list would doubtless have been 

 very much longer. In addition to our own collections we have 

 been favoured with some interesting gatherings made by means 

 of the surface-net, off the coast of Ireland, by Mr. E. C. 

 Davison, to whom our best thanks are due. Our notes have 

 been considerably enriched from this source. 



Fam. Calanidae, Dana. 



Subfam. C alanine, Dana. 



Genus C alan us, Leach. 

 (Cetochilus, Roussel de Vauzeme.) 



Galanus finmarchicus (Gunner) . 

 Abundant in the open sea and between tide-marks. 



Genus Paeacalanus, Boeck. 



(Calanus, Claus.) 



Paracalanus hibernicus } n. sp. PI. VIII. figs. 1-3. 



Anteroinferior angle of the cephalothorax slightly produced. 

 Anterior antenna? of male and female alike, slender, a little 

 longer than the cephalothorax, thick at the base and tapering 

 gradually to the extremity, twenty-five-jointed ; the nine basal 

 joints (except the first, which is very large) broader than long, 

 the succeeding joints being from twice to thrice as long as 

 broad, except the terminal one, which is very short ; each 

 joint bears on its outer margin one or two short seta?; and the 

 seven or eight proximal joints are produced into a short median 

 spine or tooth; the last joint has one long and two small seta?; 

 the penultimate, one very long seta. Both branches of the 

 posterior antenna? stout, and nearly equal in size, densely setose 

 at the apex. Mandibles strong, with a largely developed palp. 

 Maxilla? and upper maxillipeds stout, and densely beset with 

 marginal seta?. Lower maxillipeds tapering, slender, and 

 bearing fine plumose seta?. Swimming-feet having the inner 



