Fleming's egg-urchin. lb'5 



did new species before us, first found in deep water in 

 Zetland, and since taken by Mr. Ball, who has long con- 

 sidered it distinct from any described species, off Youghal, 

 on the south-west coast of Ireland, in very deep water, 

 and by him has been named after its discoverer. It is 

 by far the finest British species. 



In its form it is somewhat conico-globose. The pores 

 of the avenues are arranged in oblique rows of three pairs 

 each. These rows are sub-parallel, the last pair of the 

 one row being parallel with the first of the next. Trans- 

 verse ridges divide the pairs of pores. On each ambulacral 

 plate there is one primary tubercle, bearing a primary 

 s[>ine, with two or three irregularly-placed secondary spini- 

 ferous tubercles near it. On the lower half of the body 

 the number of secondary spines is greatly increased. The 

 inter-ambulacral plates of the lower half have two or three 

 primary spines each, and several secondaries, while on 

 those of the upper part the primaries are sometimes want- 

 ing, though when present generally longer and thicker, 

 and the number of secondaries is considerably diminished. 

 The tubercles of the primaries over the whole surface are 

 elevated on very prominent bases. The ovarian plates 

 have a few secondaries scattered irregularly over them. 

 The madreporiform tubercle is prominent, very large, 

 broadly heart-shaped and compact. The ground colour 

 of the surface is yellow ; two broad longitudinal stripes of 

 orange-red blending into the yellow at their edges run 

 down each division of ambulacral and inter-ambulacral 

 plates. The spines are yellowish-white, with purplish 

 bases. The stria} which groove their surfaces are more 

 numerous than in the other British Urchins, and the 

 intermediate ridges very narrow, though slightly broader 

 than the striae. There are no transverse striae on the 



