CLASS I 



ECHINOIDEA 



287 



where slightly petaloid, widely open distally : pore-pairs few and iiicreasingly 

 far apart. Peristome central, pentagonal, with small 

 jaws. Periproct between the peristome and posterior 

 edge of the test. Cretaceous to Recent. 



Subgenus Scutellina Ag. Periproct small, marginal or more 

 or less supra- or infra-marginal. Tertiary. „ 



Sismondia Desor. Test sub -pentagonal or ovoid, Echinoeyamus piuccutus 

 depressed, inflated at the margin. Petaloid parts of mocei •%ciiy'''y^ ^^'^' 

 the Jmh usually long, more or less open ; pore-pairs 

 not continued actinally. Tubercles minute. Eocene 

 and Miocene. 



Fibularia Lam. (Fig. 404). Test thin, ovoid, tumid 

 dorsally and at the side. ^mb short ; pore-pairs very 

 few, continued wide apart to * the margin, non-con- 

 jugated. Peristome and periproct small, sunken, close 

 together. Upper Cretaceous and Recent. 



Buna Ag. Tertiary ; Europe. 



Fig. 404. 



Fibularia suhglobosa (Goldf. ). 

 Upper Cretaceous ; Maest- 

 richt, Belgium. i/j. 



Family 3. Scutellidae Agassiz. 



Test very flat, with entire or incised margin ; limules or slits in the areas or 

 not. Ambulacral furrows bifurcating and branching. Peristome flush ; jaws flat, 



Fi(i. 405. 

 Scutella auhrotundata Lam. Miocene ; Bordeaux. .4, B, Ventral and dorsal aspects ; r, Öectioii, Vi- 



teeth superior. Eadiating partitions between the floors internally. Tertiary and 

 Recent. 



Scutella Lam. (Fig. 405). Test circular or sub-circular in outline, some- 

 times undulating or notched, broadest behind. Petaloid parts of the Amb 



