FROM THE LOWER CHALK. 



129 



A. — Species from the Lower Chalk. 

 Cyphosoma granulosum, Goldfuss, sp., 182G. PL XXIII, figs. 2 a, b, c, d. 



cidarites granulosus, 

 diadema gkanueosum, 



Echinus Milleri, 



Echinus granulosus, 



CiDARITES granulosum, 



Diauema — 



Cyphosoma — 

 — Milleri, 



— Konigt, 



Phymosoma granulosum, 

 Cyphosoma — 

 Phymosoma — 

 Cyphosoma — 



Goldfuss. Petrefact. Gcrmaniae, pi. fig. p. 122, 182C. 

 Agassiz. Prod., Mem. Soc. des Sc. Nat. de Ncufchatel, t. i, 

 p. 189, 1836. 



Besmoulins (pars). Etudes sur les Ecbinides, p. 294, 

 No. 68, 1837. 



Dujardin. In Lamarck's Anim. sans Vertebres, 2e^d., 



t. hi, p. 372, 1840. 

 Geinitz. Charakt. der Schict. und Petref., p. 90, 1842. 

 Morris (pars). Catalogue of British Fossils, p. .t1, 1843. 

 Reuss. Verstein. der Bohra. Kreideform., p. 58, 1846. 

 Agassiz et Desor (pars). Catalogue rais. des Echinid., 



p. 351, 1848. 

 Bronn. Index Palseontologicus, p. 381, 1848. 

 B'Orbigny. Prod. Pal. strat., t. ii, p. 273, fit. 22, 1850. 

 Bronn. Lethsea Geognost., Kreide-gebirges,pl. xxix, p. 186, 



1851. 



Forbes. In Morris's Catalogue of British Fossils, 2nded., 

 p. 75, 1854. 



Desor. Synops. des Echinid. foss., p. 87, 1856. 

 Woodward. Mem. Geol. Surv., Dec. V, p. 1, 1857. 

 Ilupe. Hist. Nat. Echinod., p. 508, 1862. 

 Cotteau. Pal. Fran9aise, Ter. Cr6tace, t. vii, p. 685, 

 pi. 1169, 1865. 



Test large, circular, depressed, convex on the upper surface, inflated at the sides, and 

 flattened below ; poriferous zones wide and straight in the upper third, narrow and undu- 

 lated at the ambitus and base ; pores largely bigeminal in the wide upper third, and 

 unigeminal in the rest of the zones ; ambulacra narrow above, wide below, with two rows 

 of large tubercles, twelve in each ; inter-ambulacra with two rows of primary tubercles in 

 the middle of the area, secondary tubercles wanting in young specimens, and only slightly 

 developed in the largest tests ; mihary zone wide, depressed, and naked above, narrow 

 and graimlar below ; mouth-opening small and circular ; peristome with shallow entaillcs ; 

 discal opening large, and widely pentagonal. 



Bmensions. — Height eight tenths of an inch ; transverse diameter one inch and eight 

 tenths. 



Bescriplion. — This Urchin resembles C. K6ni(ji in so many points of structure, the 

 absence or rudimentary condition of the secondary tubercles excepted, that it may pro- 

 bably be only a variety of that species. It has, however, been treated by different sys- 



17 



