102 PEOF. P. M. DUNCAIS'S KEVISION OE THE 



vol. vii. p. 707. WrigJif, 1870, Pal. Soc, Monogr. Brit. 

 Cret. 'Ech. vol. i. pt. iii. p. 116. Gregory, 1889, Ann. ^ Mag. 

 Nat. Hist. ser. 6, vol. iii. p. 490. {AiJiended.) 

 Syn. Q-lyphocyplms (pars). 



Test small, tumid in circular or subpolygonal marginal outliae, 

 depressed, snbconical or tumid dorsally, tumid actinally. Epi- 

 stroma well developed. 



-Apical disk small, with tlie antero-lateral basal plates narrow 

 and united ; postero-lateral basals moderate in size, united to 

 the antero-lateral basals, and meeting anteriorly to the periproct. 

 Posterior basal absent iu the type, but its impression left between 

 the postero-lateral radial plates, both of which enter the peri- 

 proctal area, denotes that it was broad from side to side and low. 

 The anterior and antero-lateral radial plates are excluded. Peri- 

 proct oval in shape, somewhat posterior. 



Ambulacra straight, narrow, with some high plates placed 

 abactinally to very low ones ; two vertical rows of imperforate, 

 crenulate, primary tubercles ; mamelon globose, boss expanded, 

 small abactinally, largest below the ambitus, where sometimes 

 one may occupy nearly all the breadth of an ambulacrum ; 

 surrounded by stout and irregularly placed miliaries, or by com- 

 pressed ridges which radiate from the tubercles. Poriferous 

 zones narrow, pairs in very slight arcs, usually in triplets, and 

 then the plate is made up of three low primaries with straight 

 transverse sutures ; or with four or even five pairs, but then the 

 fourth and fifth pairs are in low primary plates independent of 

 the high compound one. There may be some grooving of the 

 ambulacral sutures and a continuity of ridges between the eleva- 

 tions, on which pairs of pores are placed, and ridges coming from 

 the circular rows of miliaries around the interradial tubercles. 



Interradia with two vertical rows of primary tubercles slightly 

 larger than, but otherwise resembling, those of the ambulacra ; 

 miliaries radiating from the primaries compressed from side to 

 side, or tear-shaped. The larger tubercles are actinal, and usually 

 they have a circle of granules aground the radiating series of com- 

 pressed miliaries. Transverse coronal sutures simply and narrowly 

 grooved. 



Peristome small, sunken, with very small branchial incisions. 



Fossil. Cretaceous : England, Europe. 



