122 



GLYPHOCYPHUS 



EcniNOPSis LATiPOKA, Agassiz Desor. Ibid., p. 351, 184G. 



— CONTEXTA, Agassiz et Besor. Ibid. 



— DEPRESSA, Agassiz et Desor. Ibid. 



— CONTEXTA, Bronn. Index Palseontologieus, p. 447, 1848. 



— DEPRESSA, Bronn. Ibid. 



— LATiPORA, Broun. Ibid. 



— PUSILLA, Bronn. Ibid. 



Arbacia radiata, Bronn. Ibid., p. 91, 1848. 



Temnopleurus PULCHELLUS,)Sor?^we^. Ours, fossiles du Dep. de I'Eure, p. 31, 1850. 

 Glypticus Koninckii, Forbes. In Dixon's Geology of Sussex, p. 340, tab. xxv, 

 fig. 30, 1850. 



EcHiNOPSis PUSILLA, Forbes. In Dixon, ibid., tab. xxv, tig. 31, 1850. 



— — Giebel. Deutscblands Petrefacten, p. 320, 1852. 

 Glyphocyphus pclchellus, d'Archiac et Jules Haime. Descript. Nunimilites de I'liide, 



p. 202, 1854. 



EcHiNOPSis PUSILLA, Morris. Catal. of Brit. Fossils, 2nd. ed., p. 78, 1854. 



— LATIPORA, Pictet. Tiaite de Paleontol., 2e ed., p. 242, 1846. 

 CONTEXTA, Pictet. Ibid. 



— DEPRESSA, Pictet. Ibid. 



— PUSILLA, Pictet. Ibid. 

 CyPHOSOiVIA RADIATUM, Pictet. Ibid. 



Glyphocyphus radiatus, Desor. Synopsis des Echinides fossiles, p. 103, tab. xvii, 

 figs. 1—3, 1856. 



— — Cotteau et Triyer. I3c!iinides du dep. de la Sartlie, p. 185, 



pi. xxviii, figs. 7 — 12, 1859. 



— — Dvjardin et Ihipe. Hist. nat. desEchinod., p. 513, 1862. 

 Temnopleurus pulchellus, Co^Mflnrf. Gcol. et Pal. dela prov. de ConstantJue, p. 294, 



1863. 



Glyphocyphus radiatus, Cotteau. Paleout. Fran9., Ter. Cretace', t. vii, p. 535, 

 pi. 1127, 1128, 1863. 



Test small, circular, inflated, subglobular, rounded at the border and concave at the 

 base ; ambulacra very narrow, witli two rows of tubercles, alternate, irregular. Poriferous 

 zones narrow, straight ; simple pores in single obhque pairs. Inter-ambulacra with two 

 rows of small tubercles, areolae radiated, plates grooved at the lower border ; apical disc 

 solid, forming a narrow, elongated, subpentagonal ring, having the genital and ocular 

 plates almost of equal length ; oculars finely granulated ; vent large, oblong. 



Dimensions. — Height five twentieths of an inch ; transverse diameter eight twentieths 

 of an inch. 



Descripiion. — This small Urchin has been a great puzzle to Palaeoutologists, as proved 

 by the long list of synonyms given above. The test is circular, inflated, and subglobular; 

 rounded at the sides, and concave towards the base (figs. 1 a, b). The ambulacral areas 

 (fig. 2 e), about half the width of the inter-ambulacral, have two rows of small tubercles, which 

 form an alternate series on each side of the area ; they are largest at the ambitus, smaller 



