692 GEOLOGICAL SURVEY OF IOWA. 



In several specimens, some of the plates originally closing 

 those apertures are still remaining*. 



This species is distinguished by its stellate outline, the angularly concave form of 

 the pseudambulacral areas, the elevated acute margins of the radial plates, the trun- 

 cate summit, prominent interradial plates, and quadrangular ovarian apertures. 



Fig. 12 a. Lateral view of a small specimen. 



Fig. 12 b. Summit of the same. ( The ovarian apertures are represented with the sides 

 too much curved.) 



Geological formation and localities. In the Kaskaskia limestone : Chester 

 and Prairie du Long, Illinois ; near Huntsville, Alabama. Dr. TROOST 

 cites this species from Cherokee county, Tennessee. 



Peiitremites godoni. 



PLATE XXV. FIG. 13 a, b. 



Kentucky asteroid fossil : PARKINSON, 1808, Organic Remains, edition of 1833, pa. 235, 



pi. 13, f. 36 & 37. 

 Encrina godoni : DE FRANCE, 1818, Diet. Sci. Nat, T. 14, 



Encrinites florealis : SCHLOTHEIM, 1820, Petrefak. I, 339. 



Pentremites florealis : SAY, 1822, SOWERBY, Zool. Journal, Vol. ii, pa, 311, tab. ii, f. 2. 

 Pentremites florealis : TROOST, Trans. Geol. Soc, Pa. Vol, i, pa. 229, pi. 10. 

 P entremites florealis : RCEMER, 1852, Monog. Blast, pa. 353, pi. 14, f. 1, 2, 3, 4; and 



pi. v, f. 8. 



Pentremites godoni : SHTJMARD, Descript. New Species Blastoidese, Trans. Acad. St.Louis, 



Vol. i, no. 2. 



BODY ovoid, short, subtruncate below, obtusely pentangular, 

 stelliform in outline. Basal plates forming a small pentagonal 

 moderately convex disc, with the spreading upper joint of 

 the column usually attached, and presenting a small papilli- 

 forrn elevation. Radial plates extending almost rectangularly 

 to the base of the pseudambulacral areas, abruptly bent and 

 obtusely angular in the middle of the base : sides nearly 

 parallel, deeply forked for the reception of the pseudambu- 

 lacral areas. Interradial plates long lanceolate, not reaching 

 to the summit. Pseudambulacral areas long lanceolate, reach- 

 ing nearly to the base of the calyx, very gradually widening 

 above, convex, each side curving to a median suture which 

 is more elevated than the sides. Poral plates narrow, crowded, 



* See observations on the structure of the summit in the Genus PENTREMITES in a 

 paper entitled " Descriptfons of New Species of Blastoideae", by Dr. B. F. SHUMARD, in 

 Trans. Acad. Scien. St.Louis. Vol.i, no. 2. 



