272 



MICRASTER 



PUNCTATUS, 

 COR-ANGUINUM, 



PUNCTATUS, 



• — COR-ANGUINUM, 



PUNCTATUS, 



- COR-ANGUINTTM, 



MicKASTER cor-anguinum:, 



Spatangus COR-ANGUINUM, Goldfuss. Petrefacta Germaniae, vol. i, p. 157, 



pi. xlviii, fig. 6, 1829. 



— — De Blainville. Diet. Sc. Nat., t. xl, p. 135, 1830. 



De Blainville. Ibid. 

 Agassiz. Prodrom., Mem. Sc. Nat. Neuchatel, t. i, 



p. 184, 1835. 

 Besmoulins. fitudes sur les Echinides,p. 402, 1837. 

 Desmoulins. IbiJ. 



Agassi:. Catal. Syst. Ectyp. foss., p. 2, 18-40. 

 Dujardin. In Lamk. Anim. sans Vert., 2ud ed., t. iii, 



p. 328, 18-40. 

 Dujardin. Ibid. 

 Geinits. Charakteristik. Petref. Sachs-bohm. Kreide- 



gebirges, p. 91,1842. 

 — Morris. Catalogue of British Fossils, p. 54, 1843. 



— — Agassiz et Desor. Catal. rais. des Ech., Ann. Sc. 



Nat., 3e ser., t. vii, p. 23, 1847. 



— — d'Orbigny. Prodrome Pal. Strat., t. ii, p. 269, 1850. 



— — Sorignet. Oursins foss. de I'Eure, p. 59, 1850. 



— — Forbes. Mem. Geol. Surv., decade iii, pi. x, 1850. 



— — Bronn. Letbsea geognost., Kreidegebirge, p. 200, 



1852. 



— — d'Orbigny. Paleontologie Fran9aise, Terr, cretace, t. vi, 



p. 207, pl. 867 (pars), 1852. 



— — Forbes. Morris, Catal. Brit. Fossils, 2nd ed., p. 83, 



1854. 



— — Eebert. Tabl. Foss. de la Craie de Meudon, Mem. 



Soc. Geol. de France, 2e serie, t. v, pl. xxix, 

 fig. 15, 1854. 



— — Desor. Synopsis des Echinides fossiles, p. 364, 1858. 



— — Cotteau. Ecliinides de la Sarthe, pl. Iv, figs. 5 — 10, 



p. 326, 1860. 



Diagnosis. — Test cordiform, length and width nearly equal. Upper surface more or 

 less inflated in difi^erent specimens ; enlarged and sinuous before, contracted and tapering 

 behind ; the greatest diameter at the anterior third. Upper surface convex ; the anterior 

 half declining obliquely from the disc to the anteal sulcus, and the posterior half 

 forming a curved carinal ridge from the disc to the anal area ; posterior border flat, 

 scooped out, and inclined inwards ; vent above opening under the rostrated carina. 

 Under surface convex ; anteal sulcus equally hollowed throughout, from the disc to the 

 mouth ; petaloid ambulacra unequal in length and slightly depressed ; mouth-opening 

 near the border, with a very stout under lip. 



Dimensions. — Height, \\ inch ; length, 2^^ inches ; width, 2^ inches. 



Description. — This common Chalk Urchin has been long known to naturalists, and its 

 flint moulds, collected from the Chiltern downs, were first figured by Plot in his ' History 

 of Oxfordshire,' then by Lister and Llhwyd, and its test by Breynius, Klein, Van Phelsum, 



