lo2 Messrs. Brady and Robertson on Marine 



flagelliform appendage ; that of the male much swollen, the 

 last joint forming a sort of claw in front of the large vesiculi- 

 form swelling. Mandibles bearing a small one-branched (?) 

 palp. Second pair of maxillipeds setose on the anterior margin, 

 tei-minating in a long and slender claw. Inner branch of the 

 first pair of swimming-feet nearly twice as long as the outer, its 

 first joint longer than the entire outer branch ; second joint 

 short. Fifth pair of feet well developed, biarticulate in the 

 female ; in the male uniarticulate, much broader, rounded and 

 fringed with shorter and stronger spines. Length -^ of an 

 inch. 



This species Avas taken plentifully in a pool above high- 

 water mark on the shore south of Clifden in Connemara. 



Genus Idya, Philippi. 



(Tisbe, Lilljeborg.) 

 Idyafurcata (Baird). 

 Extremely common in littoral situations on weeds ; also 

 taken in the surface-net in sheltered bays. 



Genus Westwoodia, Dana. 



L Westwoodia nohilis (Baird). 

 On weeds in Yentry Bay, taken by Mr. E. C. Davison. 



2. Westwoodia minuta, Glaus. 

 Dredged in Westport Bay ; rare. 



Genus Ilyopsyllus, nov. gen. 

 (l\vs, mud ; \j^v\\os, a flea.) 



Corpus tumidum, gibbosura. Anteunse antiea) bre\-issimae, appen- 

 dicem ensiformera gerentes, 5-articulatae, parte basali magnopere 

 dilatata ; antennae postica3 validae, ramo secundario carentes. 

 Mandibulae parvulae, palpo simpliei bisetoso. Pedes primi pans 

 valide armati, ramo interno 1-, externo 3-articulato ; seqiientium 

 parium rami ambo 3-artieulati. Abdomen breve, versus extremi- 

 tatem attenuatum ; setae caudales spathulatae. 



Ilyopsyllus coriaceus^ n. sp. PI. IX. figs. 1-5. 

 Body very tumid; seen laterally the ventral line is almost 

 straight, the dorsal excessively arched, so that tlie cephalo- 

 thorax forms almost a semicircle ; seen from below, the outline 

 is like that of a spear-head rounded off in front ; greatest 

 width situate in the middle, and equal to half the entire length 

 of the body ; posterior half abruptly tapered. First cephalo- 

 thoracic segment very large, forming half the length of the 



