GASTROPODA. 119 



Remarks — This form resembles Earyzone itys Hall, but lacks revolving striae. It is 

 common in the Mineola of Ralls County, but good specimens are not easily secured. 

 The best in our collection is shown in figure 9 of plate 28. 



Euryzone lucina (Hall) 



Plate 26, figure 14 



1843. Euomphalus? rotundus Hall. Geology of N. Y., pt. 4, Surv. Fourth Geol. Dist., 

 p. 172, f. 4. 



1861. Pleurotomaria Lucina Hall, Descriptions of New Species of Fossils, etc., p. 14. 



1862. Pleurotomaria lucina Hall, Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 42, 

 pi. 5, fig. 12. 



1876. Pleurotomaria rotunda and P. Lucina Hall, Illustrations of Devonian Fossils: 



Gastropoda, pi. 18. 

 1879. Pleurotomaria Lucina Hall, Nat. Hist. New York, Paleontology V, pt. 2, pp. 



67-68, pi. 18, figs. 1-11. 

 1909. Euryzone lucina Grabau and Shimer, North American Index Fossils, I, p. 645, 



fig. 879c. 

 Hall's description — "Shell subglobose, or obliquely ovoid-conical. Spire moderately 

 elevated; apex minute. Volutions about four, gradually expanding to the last one, which 

 becomes very regularly ventricose, with the aperture expanded and nearly round, 

 extended on the lower side, with a shallow notch on the anterior margin; upper side of 

 the volutions very symmetrically convex; suture neatly defined, slightly canaliculate; 

 lower side of the body-volution convex in the middle, and abruptly curving into the 

 umbilical depression. Surface beautifully cancellated by concentric and revolving 

 striae, which, in many specimens, are of equal strength. Periphery marked by a moder- 

 ately wide band, on which the striae are turned abruptly backwards; this band is limited 

 by stronger striae or narrow ridges on each side, sometimes with one or two slender 

 revolving striae within the limits of the band, marking a narrower space, which is often 

 crenulated by the concentric striae." 



Remarks — Only one good specimen is in our collections, and the surface markings 

 are not present on it though the shell is preserved. Owing to an incrustation on the 

 shell it is not possible to determine whether a band is present. All specimens from 

 Missouri are from the Mineola of Ralls County. 



Genus Spiroraphe Perner 



Spiroraphe arata (Hall) 

 Plate 30, figures 1 and 2 



1861. Pleurotomaria arata Hall, Descriptions of New Species of Fossils, etc., p. 14. 



1862. Pleurotomaria arata Hall, Fifteenth Rep. N. Y. State Cab. Nat. Hist , p. 42, 

 PI. 5, fig. 13. 



1876. Pleurotomaria arata Hall, Illustrations of Devonian Fossils; Gasteropoda, pi. 



17. 

 1879. Pleurotomaria arata Hall, Pal. N. Y., V, pt. 2, p. 64, pi. 17, figs. 1-8. 

 1909. Spiroraphe arata Grabau and Shimer, North American Index Fossils, I, p. 645, 



fig. 880. 



Hall's description — "Shell depressed-suborbicular or obliquely hemispheric. Spire 



moderately elevated; volutions four or more in the entire shell, depressed-convex or 



flattened upon the upper side, and rounded below, gradually enlarging from the apex — 



the outer half of the body-volution being ventricose. Aperture somewhat transverse. 



