North American index fossils, invertebrates . Pedro of California; also Recent on Pacific coast. XXL MoRTONiA , of medium size, more or less circular to subpenta-hedral, with swollen instead of sharp borders; ambulacral petals ECHINODERMA TA—ECHINOIDEA. 593 long, open at the ends; ambulacral grooves on under side singleor bifurcating twice; periproct between peristome and 33. M. quinquefaria Say. wider posteriorly, but in general subcircular; periproct approximately at two fifths of the distance from margin to
North American index fossils, invertebrates . Pedro of California; also Recent on Pacific coast. XXL MoRTONiA , of medium size, more or less circular to subpenta-hedral, with swollen instead of sharp borders; ambulacral petals ECHINODERMA TA—ECHINOIDEA. 593 long, open at the ends; ambulacral grooves on under side singleor bifurcating twice; periproct between peristome and 33. M. quinquefaria Say. wider posteriorly, but in general subcircular; periproct approximately at two fifths of the distance from margin to of Georgia and Cedar Keys, Florida. 34. M. rogersi Conrad. , with peristome more strongly depressed than in preceding; ambulacral petals wider, open in front; periproctnearer to margin than in preceding. (Type of genus.)Vicksburgian of Georgia and Mississippi. XXII. Mellita flat as in Scutella, but with five or six usually closed lunules,or more rarely open cuts, one at the end of each ambulacrum, and.
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Keywords: ., bookcentury1900, bookdecade1900, bookidn, booksubjectpaleontology
