>KIKU V 



EUECHINOIDEA SPATAXGOIDEA 



i I :>, 





.////./' in ;i groove, with small, simple, distant pairs of pores; the other Amb 

 flexuous, with comma-shaped pores placed obliquely to one another. Periproct 

 supra-marginal. Upper Jura and Lower Cretaceous. 



Sub Order B. SPATANGOIDEA. Duncan. 



J't ristome ecmitrii' in /////, rarely pentagonal in flu- mlulf, usimlli/ with a 

 t rim- liilirinn, h-kiml u'hirh is a long plastron loini<// //////>///// /// the posterior 

 Jtiiiiitliti-i-ii ilitxiniiliir. Interambulacra with a single plate nl tin' 



l > ri*f initial margin; the postero -lateral areas usually unsymmetrical //'////////. 



Fascioles present or /> ///. 



Family 1. Ananchytidae. Desor. 



Test ovoid "/ tvb-cordiform in marginal outline, tall or depressed, and with large 

 /Jut'*. Ambulacra in a bivium and trivium, nearly similar, flush, apetalous ; pairs 

 of pores largest near the apex and at the peristome, may be uniporous. Periproct 

 nii-iiiUi- in jHMititnt. Cretaceous to Recent. 



/:'<///// 'H-nri/x, Breyn. (Ananchi/tes, Mercati), (Fig. 392). Test large, oval in 

 marginal outline; high, rounded, or keeled apically, flat actinally. Amb 

 biporous, the pairs of pores well 

 k-vi'loped abactinally, but becom- 

 ing smaller, closer, and oblique 

 toward the ambitus, where they 

 are more distant. Posterior Amb 

 actinally long and broad, the pairs 

 small, and pores oblique. Peri- 

 stome oval, broader than long. 

 Periproct infra - marginal, pos- 

 terior, oval. Apical system elon- 

 gate. Very abundant in the 

 Upper Cretaceous. E. ovata, 

 Leske sp., often attains a very 

 large size. 



/In! aster, Ag. (Fig. 393). Test 

 ovoid in marginal outline, flat 

 actinally, tumid and high abactin- 

 ally. Anterior Amb in a shallow 

 groove. Peristome elliptical, 

 broadest transversely. Periproct 

 supra - marginal, oval. A] i -. 1 1 

 system elongate. Cretaceous and 

 Miocene. 



0/aster, DeSOr. Test Small, Echtnooory, ovata, Leske sp. Wliitc chalk ; HaWcm, West- 



tumid. Anterior Amb sometimes pha j ia - ; B > P &1 * a " d \ eutral view > Vs . c, Doo^enti 



system, enlarged. D, Portion of Amb and I Amb areas. 1/1- 



in a shallow groove. Peristome 



oval, broadest transversely. Periproct supra -marginal, circular or ovoid. 



Apical system elongate. Cretaceous. 0. pilula, Ag. sp. 



Hemipneustes, Ag. Test large, ovoid in marginal outline, high and tumid 

 dorsally, flat actinally. Anterior Amb in a deep, narrow groove extending to 



FIG. 392. 



