186 TWENTT-FOVRTE REPORT ON THE StATE MuSEUM, 



Pentameeus Littoni Hall. 

 (Pal. ¥. T., Yol. 3, p. 262.) 



The Pentamerus Littoni is of the same type as the one just 

 described; and in the collection now under examination there are 

 two or three specimens which may be referred to this species. Its 

 general aspect is more gibbous and cylindrical than the preceding. 



The reference of this species in Pal. [N'. Y., vol. 3, to the probable 

 age of the Lower Helderberg, should doubtless be corrected ; and 

 since it is well known that species of both the age of Lower Helder- 

 berg and Niagara are found mingled in the locality there cited, it is 

 almost certain that the Pentamerus Littoni is from the Niagara 

 group. 



MlJECHISONIA PETILA n. SJ). 



Shell small, spire elevated, slender and regularly tapering from the 

 base to the apex ; volutions about twelve, gently and regularly 

 expanding from the apex, moderately convex, somewhat obtusely sub- 

 angular below the middle, last one scarcely ventricose. Aperture 

 subrhomboidal. 



Surface unknown. 



Length of specimen one inch ; diameter of last volution, seven- 

 twentieths, and height four-twentieths of an inch. 



Formation and looality. In limestone of middle Silurian age, near 

 the Falls of the Ohio. Cabinet of Dr. James Knapp. 



EuoMPHALus (Cyclonema) eug^lineata n. sp. 



Shell depressed turbinate, consisting of three or more rounded, 

 rapidly increasing volutions, which are marked by ten or twelve 

 strong, sharply elevated, revolving lines, having smaller ones between 

 them ; the two sets of lines becoming more equal below the center 

 of the volution ; the whole crossed by irregular lamellose transverse 

 lines of growth, which give a very rugose character where they cross 

 the revolving lines. Aperture rounded ; form of base and columella 

 not determined. 



This species bears considerable resemblance to Euomjphalus carinatus 

 Sow., from the upper Silurian of England, as figured in Murchison's 

 Siluria, but differs in having a less number of revolving carinse, and 

 in the possession of the intermediate lines, as also in the character of 

 the transverse strige. 



Formation and locality. In limestones of the age of the Niagara 

 group at Louisville, Ky. Cabinet of Dr. James Knapp. 



Ill^nus coenigeeus n. sp. 



Among the fossils in Dr. Knapp's collection from the Niagara 

 limestone, near Louisville, Ky., there is a specimen of LllcBnus, 



