BRITISH FOSSILS. 



When the test is looked upon from above, the deep wavy furrows 

 are those of the interambulacral sutures. Below, the indentations 

 are so slight that the surface at first glance resembles that of a 

 Salmacis. 



The mouth is less than one third of the diameter of the test, 

 and one fourth wider than the breadth of the genital disk. It 

 is very obscurely ten-notched. The ambulacral arches are seen 

 within it, large, complete, and set obliquely. 



The apical disk is composed of five perforated genital and five 

 perforated ocular plates surrounding the vent. The genital plates 

 are nearly equal, very elevated and prominent, with steep, smooth, 

 slightly excavated sides and triangular summits covered with 

 minute secondary tubercles (innermost) and granules. The madre- 

 poriform body is small and combined with the usual plate, the 

 contour of which it scarcely disturbs. The genital pores are placed 

 in the lowest and outermost portion, the smooth triangular pro- 

 jection in front of the base of each plate. The eye plates are large, 

 pentagonal, and smooth, except a large obscurely defined gibbosity 

 or rudimentary tubercle rising on their centres immediately above 

 the eye-perforation, which is situated at their outer margins. 



The primary spines are rather short and stout, with strong- 

 articular bases. They are sulcated by about ten strong furrows ; 

 the intermediate ridges are broader than the furrov/s and as if 

 crenulated. The secondary spines appear to have been similar but 

 more slender and delicate. 



A fine specimen measures -f-^ths of an inch in breadth by -f^ilis 

 of an inch in height. Examples vary in their proportions. The 

 sulci are as strongly marked in an example little more than half 

 that size as in the large one. 



In some of the earlier lists of Crag fossils a Gidaris is mentioned. 

 This Temnechinus was probably the sea-urchin intended. 



Locality and Geological Position. Coralline Crag of Ramsholt 

 in Suffolk. I owe to Mr. Searles Wood, Mr. Charlesworth, 

 Dr. Clarke of Ipswich, and Mr. Bowerbank, the opportunity of 

 examining most of the specimens that have ever been found. A 

 fine example is contained in the Museum of Practical Geology, to 

 which it was presented by Mr. Searles Wood. 



