33 



Eryonicus hibernicus, n. sp. 

 PL V, figs. 1-2. 



In general appearance this species closely resembles E. Faxoni, 

 but is distinguished by certain Avell-marked characteristics. 

 It has the spines of the carapace confined to definite rows, and 

 not scattered thickly over the whole surface. The rostrum is 

 double, and immediately below it there is a small median 

 spine ; the latter is not present in E. Faxoni. The whole surface 

 of the carapace is more or less setiferous, being especially so 

 about the rows of spines. The spines of the median carina 

 are arranged as follows : — 



Rostrum + 1, 1, 2, 1, 1 ; 2, 2, 1, 2. 



The carina between the cardiac and branchial regions is 

 marked by five or six large spines. The lateral margin has 

 six spines on the anterior part, three in the middle, and se\^en 

 on the posterior part. The upper submarginal carina is faintly 

 seen in its front part but dies out towards the hind margin. 

 The lower submarginal carina is furnished with ten or twelve 

 medium-sized spines. Behind the orbital sinus there are four 

 small spines in a row, which curves towards the median line 

 and ends in a large spine on the anterior branch of the cervical 

 groove. There is a single spine at the point of bifurcation of 

 the cervical groove, and also one on the space between the 

 anterior and posterior branches. There is also a spine on the 

 cardiac region between the median and branchial carinae, and 

 finally, a spine on each side of the median Ikie on the hind 

 margin of the carapace. 



The abdominal median spines are arranged as follows : — 

 1, 1, 2, 2, 2, 1, 1, the last being on the basal part of the telson. 

 The double spines on the third, fourth, and fifth segments are 

 di:fferent in shape from those of other species. They are very 

 broad and the lower portions of the two spines are united ; 

 they become separate only comparatively near the tip. 

 On the second to fifth segments there is a spine at the lateral 

 edge of the tergum, and also one on the pleuron. This latter 

 spine in the sixth segment is situated at the upper posterior 

 angle of the pleuron and projects over the base of the uropods. 

 The pleura of the second segment are much broader than the 

 others ; they bear a row of teeth on their lower edge. The pleura 

 of the other segments become successively narrower until in 

 the sixth they end in a single sharp point. The pleura of the 

 first segment are merely rudimentary as Usual. The telson 

 tapers to a sharp point, and bears sm.all spines on either edge, 

 and a double converging row of spinelets on its dorsal surface. 



The eyestalks nearly fill the orbital sinuses ; each bears a 

 blunt tubercle in front, and has a fairly large lateral process 

 developed which passes outwards and downwards beneath the 

 antero-lateral angle of the carapace. 



