GASTEROPODS. 215 



Sphaerodoma medialis ( MKEK& WOKTHEN). 



Macrochilus spiratus Swallow, 1858: Trans. St. Louis Acad. Sci. .vol.1, 



p. 196. (Not McCoy, 1850.) 

 Macrochilus mediate Meek & Worthen, 1860: Proc. Acad. Nat. Sci., Phila., 



p. 466. 

 M aero chilus pulchellum Meek & Worthen, 1860 : Proc. Acad. Nat. Sci., 



Phila., p. 467. 

 Masrochilus intercalate Meek & Worthen, 1860: Proc. Acad. Nat. Sci., 



Phila., p. 467. 

 Macrochilus mediate Meek & Worthen, 1866: Geol. Snr. Illinois, vol. II, 



p. 370, pi. xxxi, figs. 5a-b. 

 Macrochilus intercalare Meek & Worthen, 1866 : Geol. Sur. Illinois, vol. II, 



p. 371, pi. xxxi, figs. 6a-b. 

 Soleniscus medialis White, 1884: Geol. Sur. Indiana, 13th Ann. Kept., 



pt. ii., p. 156, pi. xxxiv, figs. 15-16. 



Sphaerodoma mediate Keyes, 1889: Proc. Acad. Nat. Sci., Phila., p. 306. 

 Sphcerodoma medialis Keyes, 1891: Proc. Acad. Nat. Sci., Phila., p. 262. 



Shell much like that of Sph. ponderosa (Swallow), but 

 smaller, more slender, and with the spire more elevated. 



Horizon and localities. Upper Carboniferous, Upper Coal 

 Measures : Kansas City, Clinton. 



Sphaerodoma primogenia (CONRAD). 

 Stylifer primogenia Conrad, 1835: Trans. Geol. Soc. Penna.. vol. I, p. 



267, pi. xii, fig. 2. 



Fusus inhabili* Morton, 1836 : Am. Jour. Sci., (1), vol. XXIX, p. 160. 

 Macrochilus inhabilis Norwood & Pratten, 1855: Jour. Acad. Nat. Sci., 



Phila., vol. III. p. 76, pi. ix, figs. 9a-b. 

 Macrochilus primogenium Hall, 1858 : Geology Iowa, vol. I, p. 720, pi. 



xxix, fig. 11. 

 Soleniscus ? primogenius White, 1884: Geol. Sur. Indiana, 13th Ann. 



Rep., p. 157, pi. xxxiv, fig. 3. 

 Sphcerodoma primogenia Keyes, 1889: Proc. Acad. Nat. Sci., Phila., p. 306. 



Similar to Sph. ponderosa (Swallow), but smaller, spire 

 higher, volutions more rounded, suture more deeply impressed. 



Horizon and localities. Upper Carboniferous, Upper Coal 

 Measures : Kansas City. 



Subulites elongatus COXRAD. 

 Subulites elongatus Conrad, 1842 : Geol. Sur. New Fork, Emmons' Rep., p. 



392, tig. 101. 

 Subulites elongatus Hall, 1843 : Pal. New York, Vol. I, p. 182. 



Shell subulate, composed of seven to eight volutions, which 

 are only slightly convex ; suture distinct. Aperture rather nar- 



