612 PALAEONTOLOGY OF ILLINOIS. 



middle. Aperture (as inferred from a section of the 

 whorl) transversely subreniform. Septa with a single 

 pointed lobe on each side; dorsal lobe infundibuliform, 

 the narrow portion being lanceolate ; dorsal saddle broadly 

 and very obtusely rounded; superior lateral lobe from one- 

 fourth to one-third larger than the dorsal, and having much 

 the same shape, excepting that it is proportionally wider; 

 inferior lateral lobe consisting merely of a broad rounded 

 sinuosity. (Surface unknown.) 



Should Montfort's name Aganides be retained, the name 

 of this species would become Aganides compactux. 



Greatest diameter, 2.50 inches; convexity (or breadth of 

 aperture,) 1.33 inches ; breadth of umbilicus, about 1.12 

 inches. 



This species is sufficiently distinct from all others known to us to ren- 

 der comparison unnecessary. 

 Position and locality Coal Measures ; Menard county, Illinois. 



Genus OKTHOCEKAS. 

 ORTHOCEBAS KUSHENSIS, McC ? 



PI. 30, Fig. 4. 

 Ortlwceras Xushetueig, McCHESNEY, 1860. New Pal. Foss., p. 68. 



Locality and position Upper Coal Measures. Springfield, Illinois. 



ARTICULATA. 



Genus PHILLIPSIA, Portlock. 



PHILLIPSIA (GRIFFITHIDES) SCITULA, M. and W. 



P1.3 2, Fig. 3. . 

 Phillipsia (Griffithides) scitula, MEEK and WORTHEX, 1865. Proceed. A cad. Xat. Sci., p. 270. 



SMALL, entire outline nearly elliptic. Cephalic shield 

 semi-elliptic, very convex, about one-third its breadth 

 wider than long, rounded anteriorly, and nearly straight 



