BRITISH FOSSILS. 



Decade I. Plate VI. 



ECHINUS GRANULOSUS. 



[Genus ECHINUS. Linn^us. (Sub-kingdom Radiata. Class Echinodermata. Order 

 Echinidas. Family Cidarites.) Body more or less spherical ; ambulacra! and inter- 

 ambulacral segments developed, bearing on their plates tubercles of various sizes ; anus 

 centrical, not furnished with regular calcareous valves, surrounded by a circle of five 

 ovarian and five ocular plates, all perforated ; ambulacral avenues composed of pairs of 

 pores ranged in series of three or more ; spines of one order.] 



Synonyms. Echinus granulosus^ Munster, in Goldfuss, Pet. Germ., 

 p. 125, pi. 49, f. 5 a, h. Echinus Bennettice, Kcenig, Icon. Sect., p. 35. 

 Echinus granulosus^ Grateloup, Mem. Ours, foss., p. 82. Echinus granu- 

 losus^ DuJARDiN, in second edition of Lamarck, An. sans Vert., vol. iii., 

 p. 372. Arbacia granulosa, Agassiz, Cat. Syst., p. 12. Morrts, Cat. 

 Brit. Fos., p. 48. Agassiz and Desor, Cat. Eais. des Echinides, Ann. des 

 Sc. Nat., 3rd Ser., vol. vi., Zoologie, p. 356. 



Diagnosis. E. assulis numerosis, centro-lateralibus angustissimis, dense 

 tuberculatis ; Uiberculis primariis parvis (Equalibus, regulariter in seriebus 

 horizontaMbus dispositis ; poris ambulacralibus in seriebus triplicibus verti- 

 calibus et ut in ordine simplici dispositis, sed prope orem vere subobliquis. 



This pretty and plentiful little fossil urchin was first figured as Bri- 

 tish, though very imperfectly, by Mr. Konig, in his " Icones Sectiles," 

 under the name of Echinus Bennettice, and. as a German species, by 

 Goldfuss, under the name of Echinus granulosus, given it by Munster. 

 The figure and description in the " Petrefacta Germanica " are so com- 

 plete, that we cannot hesitate to adopt the name by which this fossil is 

 known to geologists and collectors. 



In recently published catalogues it figures as a species of Arbacia, 

 and in the " Catalogue Raisonne des Echinides " of Agassiz and Desor 

 heads the second type of that genus — the section in which the tubercles 

 are described as uniform all over the surface of the shell. Echinus 

 monilis, a species bearing considerable resemblance to that before us, 

 and well known both in the fossil and recent state, having been found in 

 French and British upper tertiaries, and by myself alive in the Medi- 

 terranean, is placed by the authors quoted at the head of their first type 

 of the genus. Arbacia is a group of Echinidce, founded by Mr. J. E. 

 Gray in 1835 (Zool. Proc, part 3, p. 58), for a section of the genus 

 [i. vi.] G 



