418 



GASTEROPODA. 



[PI.A. 



FIG. 696. Platy- 

 scliisma du- 

 bium. 



PLATYSCHISMA, McCoy, 1844, Syn. Carb. 

 Foss. Ireland, p. 38. [Ely. platys, 

 wide; schisma, slit.] Obtusely conical, 

 ventricose ; spire short, obtuse, few 

 whorls; aperture very oblique, large, 

 lunate, deeply indented by the pre- 

 ceding whorl, rounded anteally, nar- 

 row retrally, with a very wide, shallow 

 sinus in the middle part of the outer 

 lip not forming a definite band, some- 

 times obsolete ; no trace of inner lip ; 

 pillar thin, a little reflected ; surface 

 smooth or only marked by the retrally 

 waved lines of growth ; umbilicus small, 

 round, open. Type P. helicites. 



ambigunm, Walcott, 1885, Monogr. U. S. 

 Geo. Sur., vol. 8, p. 188, Devonian. 



dubium, Dawson, 1868, 

 Acad. Geol., p. 309, Car- 

 boniferous. 



mccoyi, Walcott, 1885, 

 Monogr, U. S. Geo. Sur., 

 vol. 8, p. 188, Devonian. 

 PLATYSTOMA, Conrad, 1842, 

 Jour. Acad. Nat, Sci., 

 vol. 8, p. 275. [Ety. platys, broad ; 

 stoma, mouth.] Spire short; aperture 

 large, dilated ; labrum joining the body 

 whorl. This name was preoccupied for 

 a shell by Klein in 1753, for an insect by 

 Meigen in 1803, and for a fish by Agassiz 

 in 1829. The genus has been named 

 Platycfrina. Type P. ventricosum. 



affine, Billings, 1874, Pal. Foss., vol. 2, p. 

 60, Gaspe limestone, No. 8, Devonian. 



aplatum, Hall, 1876, Illust. Devonian Foss., 

 pi. U, and Pal. N. Y., vol. 5, pt. 2, p. 

 26, Schoharie grit 



arenosum, Conrad, 1842, Jour. Acad. Nat. 

 Sci., vol. 8, p. 276, and Pal. N. Y., vol. 

 3, p. 302, Low. Held. Gr. 



belial, Clarke,- 1885, Bull. U. S. Geo. Sur., 

 No. 16, p. 30, Genesee shales. 



defiguratum, Hall, 1876, Illust. Devonian 

 Foss., pi. 9, and Pal. N. Y., vol. 5, pt.2, 

 p. 24, Ham. Gr. 



deprepsum, Hall, 1859, Pal. N. Y., vol. 3, 

 p. 301, Low. Held. Gr. 



euomphaloides, Hall, 1876, Illust. Devo- 

 nian Foss., pi. 9, and Pal. N. Y., vol.5, 

 pt. 2, p. 25, Ham. Gr. 



hemisphericum, Hall, 1843, (Euomphalus 

 hemisphericua,) Geo. Rep. 4th Dist. 

 N. Y., p. 109, and Pal. N. Y., vol. 2, p. 

 288, Niagara Gr. 



grayvillense, Worthen, 1882, Bull. No. 1. 

 III. St. Mus. Nat, Hist., p. 38, Coal Meas, 

 Proposed instead of P. tumidum, M. & 

 W., which was preoccupied. 



inornatum, Walcott, 1885, Monogr. U. S. 

 Geo. Sur., vol. 8, p. 255, Subcarbon- 

 iferous. 



lichas, see Callonema lichns. 



lineatum, Conrad, 1842, Jour. Acad. Nat. 

 Sci., vol. 8, p. 276, and Pal. N. Y., vol. 

 5, pt. 2, p. 21, Up. Held and Ham. Grs. 



lineatum var. amplum, Hall, 1876, Illust. 

 Devonian Foss., pi. 9, and Pal. Foss. 

 N. Y., vol. 5, pt. 2, p. 23, Ham. Gr. 



lineatum var. callosum, Hall, 1876, Illust. 



Devonian Foss., pi. 9, and Pal. Foss. 



N. Y., vol. 5, pt. 2, p. 23, Ham. Gr. 

 lineatum var. sinuosum, Hall, 1876, Illust, 



Devonian Foss., pi. 11, and Pal. Foss. 



N. Y., vol, 5, pt. 2, p. 24. Ham. Gr. 

 minutissimum, Clarke, 1885, Bull. U. S. 



Geo. Sur., No. 16, p. 55, Portage Gr. 

 nana, see Naticopsis nana. 

 n i agarense, 



Hall, 1852, 



Pal. N. Y., 



vol. 2, p. 287, 



Niagara Gr. 

 peoriense, Mc- 



C h esn e y, 



1860, Desc. 



New Pal. 



Foss., Up. 



Coal Meas. 

 p 1 e b ei u m, 



Hall, 1876, 



28th Rep. N. 



Y. Mus. Nat. 



Hist., p. 175, FIG. 697. Platystoma ni- 



Niagara Gr. agarense. 



pleurotoma, 



Hall, 1876, Illust. Devonian Foss., pi. 



10, and Pal. N. Y., vol. 5, pt. 2, p. 30, 



Up. Held. Gr. 

 plicatum, Whiteaves, 1887, Cont. to Can. 



Pal., vol. 1, p. 118, Ham. Gr. 

 shumardi, Verneuil, 1846, (Turbo shu- 



mardi.) Bull. d. 1. Soc. Geol. d. France, 



and Pal. N. Y., vol. 5, pt. 2, p. 135, 



Ham. Gr. 

 strophium, Hall, 1862, 15th Rep. N. Y. 



Mus. Nat. Hist., p. 41, and Pal. N. Y., 



vol. 5, pt. 2, p. 25, Cornif. Gr. 

 subangulatum, Hall, 1859, Pal. N. Y., vol. 



3, p. 301, Low. Held. Gr. 



trigonostoma,Meek, 

 1871, Proc. Acad. 

 Nat. Sci., p. 169, 

 and Ohio Pal., vol. 

 1, p. 185, Niagara 

 Gr. 



tumidum, Meek & 

 Worthen, 1860, 

 Proc. Acad. Nat. 



Sci., p. 463, Up. Coal Meas. 

 turbinatum, Hall, 1861, 14th 'Rep. N. Y. 



Mus. Nat. Hist., p. 106, and Pal. N. Y., 



vol. 5, pt. 2, p. 27, Up. Held. Gr. 

 turbinatum var. cochleatum, Hall, 1876, 



Illust. Devonian Foss., pi. 10, and 



Pal. N. Y., vol. 5, pt. 2, p. 28, Up. 



Held. Gr. 

 unisulcatum, Conrad, 1842, (Pleurotoma- 



ria unisulcata,) Jour. Acad. Nat. Sci., 



vol. 8, p. 271, and Pal. N. Y., vol. 5, pt. 



2, p. 27, Up. Held. Gr. 

 ventricosum, Conrad, 1842, Jour. Acad. 



Nat. Sci., vol. 8, p. 275, and Pal. N. Y., 



vol. 3, p. 300, Low. Held. Gr. 

 Plectostylus, Conrad, 1842, Jour. Acad. Nat. 



Sci., p. 275. The name was preoc- 

 cupied. 

 hildrethi, see Macrochilina hildrethi. 



Fig. 698. Platystoma 

 trigonostoma. 



