91 



In the fifth pair they are most plentiful at the end of the 

 propodite and on the dactyl. 



Both the perfect specimens taken by the Helga are females, 

 so I can give no description of the form of the pleopods in the 

 male. The pleopods in the female are well developed and fringed 

 with long plumose setae. To the inner branch there is attached 

 a small appendix interna. 



The uropods are as long as the telson, fringed with setae, 

 rounded ; neither endopodite nor exopodite has a suture. The 

 endopodite has a strengthening midrib which bears four small 

 spines ; the exopodite has two similar ribs which end in small 

 spines on the margin. 



The gills are trichobr.mchiate, with the filaments arranged 

 in one plane. The branchial formula is as follows : — - 



— Yll, VIII. IX* X. XI. XII. XIII. XIV. 



Podobranchs. ep. 1+^P- l+ep- 1+ep. 1+ep. 1+ep. ep. — 



Arthrobranchs . — r 22222 — 



Pleurobranchs . — — — — 1 1 1 r 



In the female specimens I have seen there is a curious structure 

 situated between the coxae of the fourth pereiopods. It appears 

 to correspond to the " thelycum " of the Peneidae. It consists 

 of two lateral plates, the outer edges of which are curved upwards 

 to form sharp ridges. These extend forwards parallel to one 

 another, but posteriorly they converge, and ultimately coalesce, 

 at the same time becoming niuch flatter. Their anterior ex- 

 tremities are narrow and pointed; and between them there is 

 a third plate, roughly triangular in outline, and situated trans- 

 versely to the first two. Its anterior edge is upturned to form 

 a ridge, but this is not so high as those of the lateral plates. 

 These three plates together form a triangular hollow in the centre 

 of which appears a small opening. 



Size. — The largest specimen examined measures 72 mm. 



General Distribution. — There are very few records of this 

 species, its fossorial mode of life making it difficult of capture. 

 Probably it has a considerably wider range than is indicated 

 by the list of localities given here. It is known from the 

 south coast of England (Spence Bate), Channel Islands (Sinel), 

 France (Milne-Edwards), and the Mediterranean (Bell). 



Vertical Distribution. — LittoralJ; of burrowing habits. 



Irish Distribution. — Two female specimens have been taken 

 by the Helga, one in the Irish Sea and one in Ballynakill 

 Harbour, Co. Galway. Half -digested remains have also been 

 found on four occasions in the stomach of Raja clavata, each 

 time in Galway Bay. In one case five specimens were found 

 in one fish. 



