ORDER IV 



EUECHINOIDEA CLYPEASTROIDA 



237 



tcrnal structure investing the Amb with a double wall, but not forming con- 

 centric partitions near the edge. Tertiary and Recent. 



FIG. 382. 

 Clypeaster grandiflorus, Bronn. Miocene ; Boutonnet, near Montpellier. 1/2 natural size (after Desor). 



Plesianthus, Duncan ; Anomalanthus, Bell. Recent. 



Laganwn, Klein. Belongs properly to a separate family or sub-family. 

 Tertiary and Recent. 



Family 3. Scutellidae. Agassiz. 



Test very fiat, with entire or incised margin ; lunules or slits in the areas or 

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

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

 Recent. 



Scutella, Lam. (Fig. 383). Test circular or sub-circular in outline, some- 

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

 unequal, well-developed, nearly closed. Peristome small, central, sub-circular. 

 Periproct very small, infra-marginal. Apical system central, more or less 

 pentagonal. Tertiary. 



Sub-genus. Echinarachnius, Leske (Lendraster, Ag.) Apical system eccentric in front 

 or behind. Periproct actinal, marginal or supra-marginal. Recent. 



Echinodiscus, Breyn. (Amphiope, Lobophora, Ag.) Like Scutella, but trun- 

 cated posteriorly, and with two round or elongate lunules or slits there, 

 one in each of the median lines of the postero-lateral Amb. Tertiary and 

 Recent. 



Encope, Ag. Test with a broad notch or a lunule in the median line of 

 each Amb, and a lunule in the posterior lAmb. Miocene and Recent. 



Mellita, Klein. Test very flat, with five or six usually closed lunules, 



