104 PEOP. p. M. DUIfCAN's EETISION OP THE 



Grenus Leptdopleueus, Duncan Sf Sladen, 1885, Monogr. Foss. 

 EcTi. W. Sind, Pal. Ind. ser. xiv. p. 306. 



Test small, nearly hemisplierical or turban-shaped. 



Apical system large, solid ; basal plates large ; radial plates 

 excluded from tbe ring, their pores adoral. Epistro ma moderate. 



Ambulacra small; poriferous zones slightly sunken, pairs of 

 pores in simple series of triplets; plates composed of an aboral 

 and larger adoral primary with an intermediate demi-plate ; near 

 the apical system are a few low primary plates. Interporiferous 

 area crossed by a zigzag of raised granular ridges, uniting the 

 tubercles. 



Interradial plates scale-like, with the adoral edge overlapping a 

 corresponding depression on the aboral edge of the actinally 

 placed plate; two vertical rows of primary, plain tubercles con- 

 nected by narrow, vertical ridges. 



Peristome small, and the branchial incisions small. Transverse 

 sutural lines sunken. 



Fossil. Miocene : xlsia. 



Grenus Leiootphus, Cotteau, 1866, Fal. Frang., Terr. Gret. 

 vol. vii. p. 760, 1862-67. 



Test small, circular at the ambitus, tumid dorsally, almost flat 

 actinally. 



Apical system narrow, not solid (judging from the shape of the 

 space). 



Ambulacra with narrow poriferous zones, with simple series 

 of pairs of pores throughout ; plates compound, and in triplets of 

 primaries. Tubercles of both areas nearly equal, plain, subscro- 

 biculate, somewhat elongated at the ambitus aud dorsally, but 

 losing this character actinally. Secondary tubercles compressed 

 and elongate in the vertical direction abactinally, globular acti- 

 nally. Coronal interradial plates moderate in number (14), with 

 more or less deep grooves in the horizontal sutures. 



Peristome small ; branchial incisions very small. 



Fossil. Cretaceous : Europe. 



Grenus Coptophyma, Peron et G-authier, 1879, Ech. foss. de 

 VAlgerie, fasc. 5, p. 209, pi. xv. 



Test small, tumid at the circular ambitus, subdepressed dorsally 

 and flat or slightly tumid actinally. 



Apical system well developed, with flve large basals completing 

 the large pentagonal periproctal ring ; radial plates large. 



