BRITISH FOSSILS. 



Decade III. Plate VIL 



GALERITES (GALERITES) CASTANEA. 



[Genus GALERITES. Lamarck. (Sub-kingdom Radiata. Class Echinodermata. 

 Order Echinidse. Family Cassidulidse.) Body more or less hemispherical, always tumid ; 

 ambulacra simple, continuous, radiant ; mouth central, inferior ; anus inferior or sub- 

 marginal; tubercles perforate,] 



[Sub-genus Galerites. Body hemispheric, sub-globose, or conical ; base more or less 

 flattened ; tubercles irregularly arranged.] 



Synonyms. Forma a. major. — Nucleolites castanea, Alex. Brong- 

 NiART, Env. de Paris, pp. 100 and 349, pi. 9, fig. 14. Catopygus castanea^ 

 Agassiz, Prodr. Ech., p. 18. Pyrina castanea^ Desmoulins, Tabl. Synon. 

 des Echin., p. 258. Galerites castanea, Agassiz, Cat. Syst. Ech., p. 7 ; 

 and Ech. Foss. de la Suisse, 1st part, p. 77, pi. 12, figs. 7, 9. Desor, 

 JMonog. des Galerites, p. 23, pi. 4, figs. 12-16. Agassiz and Desor, Cat. 

 Pais, des Echin. Ann. Sc. Nat., 3rd series, vol. vii., p. 149. Galerites 

 Mothomagensis, Agassiz, Cat. Syst., p. 7, {fide Desor). 



Forma /3. minor. — Nucleolites depressa, Alex. Brongniart, Env. de 

 Paris, p. 400, pi. 9, f. 17. Catopygus depressus, Agassiz, Prodr., p. 18. 

 Pyrina depressa, Desmoulins, Tab. Synon., p. 258. Desor, JNIonog. des 

 Galerites, p. 28. Agassiz and Desor, Cat. Pais, des Echin., Ann. Sc. 

 Nat., 3rd series, vol. vii., p. 150. Galerites castanea, Agassiz, Cat. Syst., 

 p. 7 in part (fide Desor). Galerites rothomagensis, E. Sismonda, Echin. 

 Foss. Nizza, p. 51, pi. 2, figs. 8-10. Galerites Icevis, Agassiz, Cat. Syst., 

 p. 72.? Desor, Monog. des Galerites, p. 24, pL 4, figs. 8-11.? 



Diagnosis. G. corpore depresso^ ovato seu suhorbiculari, lateribus ro- 

 tundatis ; ano postico, supra-marginali ; tuberculis omnibus sub- cequalibus ; 

 poris ambulacralibus ad orem laxe confertis. 



In the " Geology of the Environs of Paris" there are two cretaceous 

 urchins from Savoy, figured under the names of Nucleolites castanea 

 and Nucleolites depressa^ which I take to be varieties of one species of 

 Galerites, and to be identical with that which is here described and 

 figured. The shght distinction in the degree of elevation of the anus 

 above the margin, noticed by Brongniart, was not sufficient to establish 

 a specific difference ; and as the smaller form was styled depressa under 

 the belief that it might be the Galerites depressus of Lamarck, the 

 specific name castanea is adopted for both varieties. 



[ill. vii.] B 



