84 PEOF. p. M. Duncan's eeyision op the 



near the peristome tliere are some small tubercles, wliich are 

 perforate and scrobiculate ; they are more developed than those 

 of the ambulacra. 



Peristome (wanting) probably small. 



Fossil. Oolitic : Europe. 



The drawing of the solitary species given by De Loriol shows 

 a globose test longer than broad, and very minutely granular ; 

 the increased size of the ornamentation actiually is very charac- 

 teristic. 



Genus incertce sedis. 



Grenus Peogonechinus, Duncan and Sladen, Pal. Ind. ser. xiv., 

 Foss. Ecli. W. Bind, p. 43, pi. x. figs. 1-4. 



Test small, moderately high, subhemispherical, concave acti- 

 nally ; margin circular and tumid. 



Apical system absent. 



Ambulacra narrow, with straight poriferous zones having 

 numerous pairs of pores directly superposed and close. The 

 plates compound, the adoral component a low broad demi-plate, 

 the middle a large primary plate carrying two small tubercles, 

 and the aboral component a low broad primary ; sutures grooved 

 and distinct ; tubercles plain, in two vertical series on each side 

 of the median line, others near the ambitus ; low granules often 

 forming ridges. 



Interradia broad ; plates low ; two persistent vertical rows of 

 plain scrobiculate primaries larger than those of the ambulacra ; 

 at the ambitus two or more vertical rows occur besides, but are 

 lost actinally and dorsally. Large granules with mamelons occur, 

 and a row near each poriferous zone has costsB passing towards 

 the pairs of pores and also to the scrobicules of the neighbouring 

 primary tubercles. Grrooves along the upper and lower sutures 

 of the interradial plates near the median line. 



Peristome circular : branchial incisions well developed, with 

 thick everted margins. 



Fossil. Eocene : Asia. 



This is a very synthetic genus, and links the Diadematidse and 

 the Temnopleuridge. 



