BRITISH FOSSILS. 



11 



26. D, Autissiodorense, Cotteai', Cat. Meth. (185]), ]). 5. m-, Wrioht, Ann. and 

 Mag. Nat. H. (1852), vol. x. p. 91. 



Locality. — Lower Green Sand, " Cracker-rock," Atherfield, Isle of Wight. (Coll. 

 Wright.) 



Section C. Spines tubular, annulated. (Diadema.) 



27. Diadema, sp. 



This specimen consists of numerous scattered plates, with portions of the dental 

 apparatus, and fragments of above 100 spines. Nearly aU the plates exhibit only 

 the smooth internal surface ; the ambulacral pores are in single file, becoming 

 a little crowded near the oral extremity ; the interambulacral tubercles appear 

 to have formed more than two rows, and are of unequal size ; they are distinctly 

 perforated and crenulated. The spines are tubular, longitudinally striated and 

 annulated (as, e. g., in the recent D. calamaria) ; the annulations are often oblique, 

 and that nearest the articular end is very prominent. These spines are cyiindrical 

 and slender ; the largest fragment measures 15 lines, with a diameter of half aline, 

 and may have been 3 inches long when perfect. 



Attention has been directed to this specimen by Mr. L. Barrett, F.G.S., who ascertained 

 that a spine from it had been inadvertently figured in pi. 10, f. 15, of Decade 3. 

 The figure is very bad, and the oblique annulations are described as spirals 

 (Micraster, Decade 3, p. 4). Several specimens, precisely similar, are in the cabinet 

 of Mr. Bowerbank, one of them has been figured in Dixon's Geol. Sussex, pi. 25, 

 f. 8, as the spine of a Cidaris. 



Locality. — Upper Chalk, Kent. (N. T. Wetherell, Esq.) 



S. P. Woodward. 



March 1856. 



