North American index fossils, invertebrates . Comanchic to Tertiary. 41. H. completus Cragin. small, subcylindrical on a rotund ovate to broadly oval base; sides subvertical btit slightly convex; summit flattish-convex;unpaired ambulacrum about as conspicuous as the others; madre-poric function shared by four genital of Texas. 598 NORTH AMERICAN INDEX FOSSILS. XXVIIL Cardiaster to Holaster, but anterior groove deeper and with angularmargin. Anal opening oval, placed in a depression in the truncateposterior face. A more or less complete marginal fa
North American index fossils, invertebrates . Comanchic to Tertiary. 41. H. completus Cragin. small, subcylindrical on a rotund ovate to broadly oval base; sides subvertical btit slightly convex; summit flattish-convex;unpaired ambulacrum about as conspicuous as the others; madre-poric function shared by four genital of Texas. 598 NORTH AMERICAN INDEX FOSSILS. XXVIIL Cardiaster to Holaster, but anterior groove deeper and with angularmargin. Anal opening oval, placed in a depression in the truncateposterior face. A more or less complete marginal fasciole present,passing beneath the anal opening. Cretacic. 42. C. cinctus Morton. (Fig. 1931, ^-/j.) Cretacic. Test cordate. Anal opening oval, situated on the truncated pos-terior face. Middle marl bed of New Jersey. XXIX. Epiaster dOrbigny. {Macraster Roemer.)Test heart-shaped, longer than broad. Anterior ambulacrumin a groove. Paired ambulacra petaloid dorsally, with elongate,unequal pores. Interambulacra swollen dorsally. Mouth opening. Fig. 1932. Epiaster ehgans, lower, lateral and upper views, X Yi- (Md. Survey.) transversely oval, swollen anteriorly and usually with projectinglip. Anal opening longitudinal, situated above the lower posteriormargin. Comanchic. 43. E. elegans (Shumard). (Fig. 1932.) , flattened above and below. Anterior groove shallow. Posterior margin truncate. Apical disk small, compact. Analopening oval, on truncated posterior margin. Characteristic of Fort Worth limestone (Washita) of Texas. 44. E. whitei Clark. (Fig. 1933,a-c.) Anal opening high on the posterior of Texas. ECHINODERMA TA—ECHINOIDEA. 599 XXX. Enallaster heart-shaped, longer than broad, with an anterior parts of the anterolateral ambulacra divergent, flexuous,tending to close, and with very unequal pore-bearing zones ofwhich the posterior are the larger. Pairs of pores oblique. Pos-terolateral ambulacra short
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