io Field Museum of Natural History — Geology, Vol. IV. 



1893. H. parastatus Clark, Johns Hopkins Univ. Circ, Vol. 12, 



No. 103, p. 52. 

 1893. H. parastatus Clark, Bull. U. S. G. S., No. 97, p, 83, pi. 45, 



figs. 1 a-m. 

 1905. H. parastatus Johns., Proc. Acad. Nat. Sci. Phil., 1905, 



p. 7. 

 1907. H. parastatus Weller, Paleontology of New Jersey, Vol. 4, 



p. 298, pi. 15, figs. 1-13. 

 This species was described from the Upper Cretaceous limestone 

 of Timber Creek, New Jersey, and has been reported from the Ripley 

 Group of Alabama. 



Five specimens of this species, Cat. No. P 10341, were collected 

 by the writer near the southern edge of the village of Pontotoc, 

 Mississippi, in the so-called "white gullies" of the Ripley Group. 



Hemiaster lacunosus sp. nov. Plate II, Figs. 1-7. 



Test small, indistinctly cordate, ventral surface moderately con- 

 vex, dorsal surface convex, strongly elevated in the posterior inter- 

 ambulacral area and gradually sloping with an indistinct anterior 

 sulcus; anterior and lateral borders inflated, posterior margin trun- 

 cated. Ambulacral areas petaloid, with straight petals situated in 

 depressions of the surface, the antero-lateral pair nearly twice as 

 long as the postero-lateral pair; poriferous zones of the paired 

 petals wide, pores transversely elongate and situated far apart. 

 Anterior petal longer but narrower than the others and situated in a 

 deep depression which grades into an indistinct anterior sulcus; 

 poriferous zones of this petal narrow and far apart; pores small, 

 round and separated by a tubercle. Interambulacral areas broad 

 and composed of large plates. Surface of the test covered with a 

 multitude of small tubercles with sunken areoles that increase in 

 size toward the peristome. The tubercles have perforated mamelons 

 and crenulated bosses, the inter-spaces being filled with microscopic 

 granulations. Peripetalous fasciole wide and distinct, moderately 

 bent inward between the petaloid areas except the two posterior 

 ones. Apical disc sunken, small and situated somewhat posterior 

 to the center of the dorsal surface, the four genital plates distinctly 

 perforated and separated by five small radial plates. Right anter- 

 ior genital plate large, convex and forming the madreporite. 

 Peristome transversely arched, bilabiate, with prominent labrum. 

 Periproct about the size of the peristome, elongated vertically 

 and situated near the top of the posterior truncation. 



