332 ECHINOBRISSUS 



ocular plates are triangular, and occupy depressions between the larger genital plates, 

 opposite the summits of the petaloid ambulacra. 



The tubercles are small on the upper surface, and larger at the base. 



The genus Echinobrissus was established by Breynius in 1732, in his important 

 memoir ' De Echinis et Echinites,' in which it was thus characterised : " Echinobrissus est 

 Echinus, cujus oris a2Jertura centrum basis fere occupat, ani vero in vertice consj)icitur, 

 a centro aliquantulum remota. et in sinu quodam ori oblique opposita."* 



Klein, who published two years afterwards, unfortunately did not preserve any of the 

 well-defined genera of his learned contemporary, and his commentator, Leske, in 1778, placed 

 the Echinobrissus of Breynius among the B;patangus of Klein. When Lamarck, in 1801, 

 instituted his genus Nucleolites, he appears not to have been aware that the same group 

 had been well figured and accurately defined sixty-nine years before by Breynius ; 

 in his great work, " Animaux sans vertebres," he reproduced his genus Nucleolites, and 

 for the first time refers to Breynius's work for figures of the species. 



M. Agassiz, in dismembering Lamarck's Nucleolites, did not restore Breynius's genus, 

 although that author was most careful to reproduce the genera established by the older 

 authors ; thus, Nucleolites columbaria, Lamk., was repeated as the type of his new genus 

 Catopy(jus, and N. ovalus, Lamk., became the type of Pyrina, whilst N. scutatus, 

 Lamk., remained the type of Nucleolites. M. d'Orbigny restored the genera so 

 well established by Breynius, and proved beyond all question that author's claim to 

 Echinobrissus ; M. Cotteau and M. Desor have both admitted the justice of his views, 

 and the genus Echinobrissus now occupies the position from which it ought never to have 

 been displaced. 



A. Species from the Inferior Oolite. 

 Echinobrissus clunicularis, Llhwyd. PI. XXIV, fig. 1 a, b, c, d, e,f,g, h, i, Jc. 



Echinites clunicularis. Llhwyd, Lithophylacii Brittanici Ichnograpli., p. 48, 1698. 



Echinobrissus planior. Breynius, Schediasma de Echinis, tab. vi, figs. 1, 2, 1732. 



Nucleolites Sowerbyi. Defrance, Die. Sciences Naturelles, tome xx.xv, p. 213, 1825. 



Clypeus lobatus. Fleming, British Animals, p. 479, 1828. 



— clunicularis. Phillips, Geology of Yorkshire, tab. vii, fig. 2, 1829. 



Nucleolites clunicularis. Blainville, Die. Sciences Naturelles, tome Ix, p. 188, 1830. 



— LATiPORUS. Agassiz, Echinoderra. Foss. de la Suisse, p. 43, tab. vii, 



figs. 13—15. 



— CLUNICULARIS. Desmoulins, Tableaux Synonymiques des Echinides, p. 358, 



1837. 



* * De Echinis et Echinites, sive Methodica Echinorum Distributione, Schediasma,' 1732. 



