^ar t'^'pecK'S of Fossils from (Jliio. 'lO'i 



as wide as the entire Avidth of tlie shell, and apparently about two-thirds as 

 wide in a dorso-ventral direction as laterally. The exact form of the aper- 

 ture on the outer side cannot be ascertained, owing to the imperfection of 

 the specimen in this part. Septa moderately concave, very closely arranged 

 in the lower part, but more distantly disposed above ; the rate of increase 

 in distance somewhat gradual to near the upper portion, where two or three 

 of the septa are slightly more crowded. In the more distant portions, 

 three chambers occupy the space of one inch, but in the lower pait of the 

 specimen, where the transverse diameter is a little more than one and a half 

 inches, they arc less than one-twelfth of an inch apart. Siphuncle of mode- 

 I'ate size and sub-centrally situated. Smface of the shell unknown. 



The spet'iiucn fioui wliicli the (k'scriptiou is taken is an in- 

 ternal cast, tiot fetuining any i)ortion of tlie shelly strnctnre, 

 but it appears to have been destitute of sti'ong surface markings. 

 It njeasures about seven inches in length by nearly four inches-/ 

 in transverse diameter at the widest part, which is near the' 

 loAver part of the outer chamber. The lower end is imperfect, 

 and measures one and a half inches in transverse diameter. It 

 is with some hesitation that I place the species, under the genus 

 (lOinplioceras, owing to the strong curvature of the shell and 

 the structui'e of the aperture, which is reversed in its relation 

 to the curvature of the shell as compared with most species of 

 the genus ; the widest portion being on the inside curvature, in- 

 stead of on the outer side. The general triangular or trilobed 

 form of the aperture, together with the greater lateral diameter, 

 would seem to ovei'balance the fact of the curvature. 



For mat ion and Locality. — In limestone of the Ujiper Helder- 

 berg group, at Smith and Price's quarries, near Columbus, Ohio. 

 Xamed in honor of Mr. E. Hyatt, from whose collection it was 

 obtained. 



Cionipiiocera§ aiupliora, n. sp. 



Pal. O., Vol. Ill, Plate 3, Fig. 9. 



Shell of large size, elongate-ovate or short sub-fusiform, somewhat rapidly 

 expanding from below upward to within a short distance of the base of the 

 outer chamber ; from which point it again contracts more rapidly to about 

 one-half the height of the outer chamber, and is then drawn out into a nar- 

 row^ neck, resembling the neck of a bottle, of a width but little exceeding 

 one-third of the diameter of the larger portion of the shell. Aperture not 

 distinctly traced, but on the side figured, there is an appearance of a deep, 

 rather narrow sinus, extending nearly one-half the depth of the outer 



