98 Dr. T. R. Wright on a new Genus of Fossil Cidaridae, 



Hemipedina perforata, Wright. 



Goniopygus 1 perforatus, Wright, Annals of Nat, Hist. S. 2. vol. viii. 

 p. 267. pi. 6. fig. 5 a-h. 



Test small, circular and depressed ; ambulacral areas with two 

 rows of small tubercles which extend from the peristome to 

 the disc ; iuterambulacral areas with two rows of tubercles, 

 seven to eight in each row, three or fovu* secondaiy tubercles 

 between the primary rows at the base ; surface of the plates 

 covered with numerous coarse miliary granules ; mouth-open- 

 ing large ; peristome rather deeply decagonal ; lobes nearly 

 equal in size ; apical disc large and foliated. 



Locality. — Pea-grit, Inferior OoUte, Crickley Hill. 

 Coll. Dr. Wright. 



Hemipedina tetragramma, Wright, nov. sp. 



Test circular, y^y ths of an inch in diameter ; ambulacral areas 

 narrow, with two marginal rows of small nearly equal-sized 

 tubercles extending from the peristome to the disk ; iuteram- 

 bulacral areas with two rows of primary tubercles, about four- 

 teen in each row, and two rows of secondary tubercles, ten in 

 each row, extending from the peristome to nearly the upper 

 surface; mouth-opening small, situated in a depression ; 

 peristome decagonal, unequally lobed. 



Locality. — Pea-grit, Crickley Hill, 

 Coll. Dr. Wright. 



Hemipedina Waterhousei, Wright, nov. sp. 

 Test small, pentagonal, rather inflated at the sides ; ambulacral 

 areas with two rows of small tubercles extending from the 

 peristome to the disc ; iuterambulacral areas with two rows of 

 tubercles, eight in a row ; scrobicular circles neatly defined ; 

 mouth-opening small ; apical disc nai'rovv and prominent. 



Locality. — Pea-grit, Inferior Oolite, Crickley Hill. 

 Coll. Dr. Wright. 



Hemipedina Bond, Wright, nov. sp. 



Test small, pentagonal, depressed ; ambulacral areas with two 

 marginal rows of close-set tubercles ; iuterambulacral areas 

 with one entire row and four short rows of tubercles, which 

 extend only as far as the equator ; tubercles of both areas 

 about the same size j base flat ; mouth moderate in dimen- 

 sions ; peristome unequally decagonal ; apical disc absent. 



Locality. — Pea-grit, Crickley Hill. 

 Coll. Dr. Wright. 



