INSTITUTE OF SCIENCE, PHILADELPHIA. 57 



M. constricta Conrad, 1835, E. .C. 



M. fonstiicla Emmons, 1858 (non Conrad), M. ; = M. contracia Conrad. 



M. constrictoides M. and Aldr., 1886, E. 



M, contracta Conrad, 1871, M. 



M. coi.ulm H. C. Lea, 1846, M. ; = M. mimita Pfeiffer. 



M crassilabra Conrad, 1833, E. C. 



M. crassilabra Lea, 1833, E. C. ; ^ M. huvierosa Conrad. 



M. denticulala Conrad, 1830 (non Tate, 1878), M. P. R. 



;!/. (iistiuis Conrad, MS., 1862, M. ; undescribed or figured. 



Ar eburneola Conrad, 1834, M, ; ^ AT deiiliculata Conrad. 



M. elevata Emmons, 185S, M. R. 



A[. exilis H. C. Lea, 1S46 (non Gmelin) ^. \ ^ M. subexilis Orbigny. 



M Gabbii Dall, 1890, P. (R. ?) ; = M. ovuKformis Gabb non Orbigny. 



M. humerosa Conrad, 1835, E. C. 



M. incrassata Nelson, 1870, P. ? 



M. inctirva Lea, 1833, E. C. (immature and indeterminable). 



M. inflexa Emmons, 1858 (non Sowerby) ; = M. siibinflexa Redfield. 



M Jewettii Carpenter, 1856, PP. R. 



M. larvata Conrad, 1833, E. C. 



M. limatula Conrad, 1834, M. P. R. 



M. minor, C. B. Adams, 1852, P. R. 



M. minuta PfeifTer, 1840, M. P. PP. R. 



M. nana Conrad, MS., 1834 (undescribed or figured), not of Marrat, 187S. 



M. olivi/ormis Tuomey & Holmes, 1857, V. \ = M. aniiqua Redfield. 



M. ovata Emmons, 1858, E. C. M. P. ; = M. semen Lea. 



y)/ ovata Lea, 1833, E. C. ; ^ M. latvata Conrad. 



M. oviformis Conrad, 1868, M. 



M. ovula Conrad, 1871, M.; = M. oviformis Conrad. 



M. ovuliforniis Gabb, i88i, P. (non Orbigny, 1842) ; ^ M. Gabbii Dall. 



M. perexigua Conrad, 1842, M. (unfigured. Like an exaggerated Willcoxii). 



M. plicata Lea, 1833, E. C. 



M. pudica Gaskoin, 1849, R. ; = j^/ chrysomelitta Redfield. 



M. roscida Redfield, i860, M. P.? R. ; = M. limatula Conrad. 



M. semen Lea, 1833, E. C. 



M. semenoides Gabb, i860, E. {Erato s. Gabb). 



M. Sowerbyi Gabb, 1873, M. (unfigured). 



M. subexilis Orbigny, M. (undeterminable). 



M. subinflexa Redfield, 1S71, M. 



M. virginiana Conrad, 1S68, M. P. R. 



Family VOLUTID^. 



Before considering the systematic arrangement of our American VohiiidcB 

 it may be well to consider the development of the group. Eliminating Can- 

 cellaria and other Toxoglossa, the group formerly called the Columellacea had 

 without doubt a common origin. The indications are pretty clear that from 



