406 



GASTEROPODA. 



[HOL. LOX. 



ovalis, Billings, 1859, Can. Nat. and Geo., 



vol. 4, p. 351, Calciferous Gr. 

 paludiniformis, Hall, 1847, Pal. N. Y., 



vol. 1, p. 171, Trenton Gr. 

 proserpina, Billings, 1862, Pal. Foss., vol. 



1, p. 28, Calciferous and Chazy Grs. 

 proutana, Hall, 1858, Trans. Alb. Inst, 

 vol. 4, p. 30, and Bull. Am. Mus. Nat. 

 Hist., p. 72, Warsaw Gr. 

 pyrene, Billings, 1862, Pal. Foss., vol. 1, 



p. 27, Black Riv. Gr. 

 reversa, Hall, 1860, Can. Nat. and Geo. 



vol. 5, p. 154, Up. Silurian, 

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



p. 294, Low. Held. Gr. 

 sw6comca,Winchell, 1863, Proc. Acad. Nat. 

 Sci., p. 21. This name was preoccupied, 

 sweeti, Whitfield, 1880, Ann. Rep. Geo. 

 Sur. Wis. and Geo. Wis., vol. 4, p. 174, 

 Potsdam Gr. 

 symmetrica, Hall, 1847, Pal. N. Y., vol. 1, 



p. 170, Black Riv. Gr. 

 turgida, Hall, 1847, (Pleurotomaria tur- 

 gida,) Pal. N. Y., vol. 1, p. 12, Calcifer- 

 ous Gr. 

 ventricosa, Hall, 1847, Pal. N. Y., vol. 1, 



p. 171, Trenton Gr. 



HOLOPELLA, McCoy, 1855, Brit. Pal. Foss., 

 3. [Ety. diminutive of Holopea.'] 

 spiral, elongate, slender, of nu- 

 merous gradually increasing whorls, 

 generally crossed by slightly arched 

 striae ; mouth circular, with the peri- 

 treme entire; base rounded, with or 

 without a minute umbilicus. Type H. 

 cancellata. 

 mira, Winchell, 1863, Proc. Acad. Nat. 



Sci., p. 22, Marshall Gr. 

 Inachus catilloides, see Euomphalus catil- 



loides. 



pervetus, see Euomphalus pervetus. 

 pervetustus, see Pleurotomaria pervetusta. 

 undalus, see Lituites undatus. 

 ISONKMA, Meek & Worthen, 1866, Proc. Acad. 

 Nat. Sci. Phil., p. 251. [Ety. isos, equal ; 

 nema, thread.] Depressed turbinate, 

 subglobose, obtusely angular around the 

 middle of the body whorl; aperture 

 subrhombic ; outer lip thin, entire ; in- 

 ner lip a little flattened in the umbil- 

 ical region ; surface ornamented with 

 transverse, very regular lines on the 

 upper side of the volutions. Type I. 

 depressum. 

 bellatulum, see Callonema bellatulum. 



depressum , Meek 

 & Worthen, 

 1865, Proc. 

 Acad. Nat. Sci. 

 Phil., p. 251, 

 and Geo. Sur. 

 111., vol. 3, p. 

 443, Ham. Gr. 

 humile, Meek, 1871, Proc. Aca>i. Nat. Sci., 



g79, and Ohio Pal., vol. 1, p. 214, Up. 

 eld. Gr. 



lichas, see Callonema licha?. 

 LBPBTOPSI8, Whitfield, 1882 Bull. Am. Mus. 

 Nat. Hist., No. 3, p. 67. [Ety. Lepeta, a 



FIG. 679. Isonema de- 

 pressum. 



genus; opsis, resemblance.] Shell pa- 

 telliform, more or less regularly round 

 or oval, apex subcentral, posterior to 

 the middle, directed backward, the nu- 

 cleus dextrally coiled; muscular im- 

 print horseshoe-shaped, open in front, 

 consisting of an irregular narrow band, 

 which expands more or less at the an- 

 terior extremities ; surface with six ra- 

 diating lines, two anterior, two poste- 

 rior, and two lateral. 

 Type L. levettii. 



chesterensis, Worthen, 

 1884, Bull. No. 2, 111. 

 St. Mus. Nat. Hist., p. 

 25, and Geo. Sur. 111., 

 vol. 8, p. 140, Kaskas- 

 kia Gr. 



levettii, White, 1882, (Pa- 

 tella levettei,) llth 



Re &o G w- of 



p. 359, Warsaw Gr. 

 Littorina, Ferussac, 1821, Tab. Syst. An. 

 Mollusques, etc. 



antiqua, see Holopea antiqua. 



cancellata, see Cyclonema cancellatum. 



wheeleri, see Naticopsis wheeled. 

 LOPHOSPIRA, Whitfield, 1886, Bull. Am. Mus. 

 Nat. Hist., vol. 1, p. 312. [Ety. lophos, 

 the keel ; speira, a whorl.] Spire ele- 

 vated, strongly keeled, and axis mi- 

 nutely perforate, when whorls are not 

 disconnected. The types are Murchi- 

 sonia milleri, Hall, and M. helicteres ; 

 but as the generic characters are not 

 very satisfactorily or clearly defined, I 

 leave the species with Murchisonia. 



cassina, see Murchisonia cassina. 



calcifera, see Murchisonia calcifera. 

 LOXONEMA, Phillips, 1841, Pal. Foss., Corn- 

 wall, etc., p. 98. [Ety. loxos, oblique ; 

 nema, thread.] Shell elongate, many 

 whorled; aperture simple, attenuate 

 above, effuse below; lines of growth 

 sigmoidal ; no umbilicus. Type L. sinu- 

 osum. 



aculeatum, Billings, 1866, Catal. Sil. Foss. 

 Antic., p. 55, Anticosti Gr. 



acutulum, Dawson, 1868, Acad. Geol., p. 

 309, Carboniferous. 



approximatum, Walcott, 1885, Monogr. 

 U. S. Geo. Sur., vol. 8, p. 191, Devonian. 



attenuatum, Stevens, 1858, (Chemnitzia 

 attenuata,) Am. Jour. Sci. and Arts, 2d 

 ser., vol. 25, p. 259, Coal Meas. 



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

 p. 296. The name was preoccupied. 

 See L. emaceratum. 



attenuatum var. semicostatum, see L. semi- 

 costatum. 



bellatulum, see Isonema bellatulum. 



bellona, Hall, 1876, Illust. Devonian Foss., 

 pi. 14, and Pal. N. Y., vol. 5, pt. 2, p. 46, 

 Ham. Gr. 



bellum, Walcott, 1885, Monogr. U. S. Geo. 

 Sur., vol. 8, p. 258, Subcarboniferous. 



boydi, see Murchisonia boydi. 



breviculum, Hall, 1879, Pal. N. Y., vol. 5, 

 pt. 2, p. 132, Ham. Gr. 



