GENERA ATH) aEOFPS OE THE ECHINOIDEA. 189 



the margin and then placed in the deep smooth grooves, ex- 

 panding and doubling into large and highly-ornamented phyllodes 

 at the peristome. 



Peristome excentric in front, pentagonal, with a highly-deve- 

 loped floscelle. Periproct inframarginal, in a special area, close 

 to the posterior edge of the test, pyriform or ovoid and longitu- 

 dinal, transverse rarely. Ornamentation small, largest actinally, 

 except in the grooves. 



Interradia greatly reduced near the apical system, usually with 

 an undulating surface. 



Fossil. Oolite : England, Europe. Cretaceous : Europe, N. 

 Africa, W. Africa, N. America ? 



Genus Eaujasia, d'Orbigny, 1855, Pal. Fran^., Ecliin. Terr. Cret. 

 vol. vi. p. 314. JDesor, 1858, Synopsis, p. 316. 



Test of m.oderate size, circular or oval in marginal outline, 

 very convex or conical abactinally ; summit slightly excentric in 

 front, rounded or acuminate ; subrostrated posteriorly. 



Apical system upon the summit, with four perforated basals. 



Ambulacra equal, similar, flush, petaloid, but open distally, very 

 short ; petals barely reaching halfway to the margin ; inner pores 

 circular, outer elongate. Actinal surface flat. 



Peristome flush, subcentral, pentagonal, with a distinct 

 floscelle. Periproct small, transverse, inframarginal. Ornamen- 

 tation very small, largest actinally. 



Fossil. Cretaceous : Europe and N. America. 



G-enus Galebocltpetjs, Gotteau, 1873, Fal. Frmi^., Terr. Jura, 

 vol. ix. p. 360. 



Test variable in size, subcircular in marginal outline, tumid 

 and subcorneal dorsally, subrostated posteriorly, and strongly pul- 

 vinate actinally. 



Apical system at the summit, subcentral or slightly posterior, 

 compact, the large madreporite irregularly produced centrally. 



Ambulacra similar, narrow, widest at the ambitus, inner pores 

 round, the outer slightly elongate as far as the ambitus, and then 

 equal, round, oblique, and separated by a nodule. Tubercles 

 small, wide apart, perforate, crenulate, and scrobiculate. 



Peristome subpentagonal, sometimes oblique, slightly excentric 

 in front, in a deep depression ; interradial margins produced and 



