272 



MICRASTER 



PUNCTATUS, 

 COR-ANGUINUM, 



PUNCTATUS, 



— COR-ANGUINUM, 



— PUNCTATUS, 



— COR-ANGUINUM, 

 MlCRASTER COR-ANGUINUM, 



Spatangus cor-anguinum, Goldfuss. Petrefacta Germanise, 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. 

 Desmoulins. Etudes sur les Echinides,p. 402, 1837. 

 Desmoulins. Ibid. 



Agassiz. Catal. Syst. Ectyp. foss., p. 2, 1840. 

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



p. 328, 1840. 

 Dujardin. Ibid. 

 Geinitz. Cbarakteristik. 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 l'Eure, p. 59, 1850. 



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



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



1852. 



— — d'Orbigny. Paleontologie Francaise, Terr, cretace", t. vi, 



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



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



1854. 



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



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

 fig. 15, 1854. 



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



— — Cotteau. Ecbinides de la Sarthe, pi. lv, figs. 5 — 10, 



p. 326, 1860. 



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

 less inflated in different 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, 1^ 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, 



