Lesueurillidae

Lesueurillidae is an extinct family of paleozoic molluscs (gastropods?) with anisostrophically coiled shells of uncertain position (Gastropoda?) (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).

Taxonomy
The taxonomy of the Gastropoda by Bouchet & Rocroi, 2005 categorizes Lesueurillidae in the superfamilia Euomphaloidea within the Paleozoic molluscs with anisostrophically coiled shells of uncertain position (Gastropoda?). This family has no subfamilies.

Genera
Genera in the family Lesueurillidae include
 * Eccyliopterus Remelé, 1888
 * Eccyliopterus abendanoni
 * Eccyliopterus alatus (Roemer, 1876) - type species
 * Eccyliopterus corniculum
 * Eccyliopterus declivis Koken, 1925 - synonym: Eccyliopterus spirillum.
 * Eccyliopterus incresens
 * Eccyliopterus ottawaensis
 * Eccyliopterus owenanus
 * Eccyliopterus regularis - synonym: Eccyliopterus princeps.
 * Eccyliopterus replicata
 * Eccyliopterus septiferus
 * Eccyliopterus tolli
 * Eccyliopterus vagrans
 * Lesueurilla Koken, 1898 - type genus of the family Lesueurillidae
 * Lesueurilla acutangulum
 * Lesueurilla bohemica
 * Lesueurilla beloitensis
 * Lesueurilla dilatata
 * Lesueurilla grandis
 * Lesueurilla helix
 * Lesueurilla infundibulum (Koken, 1896) - type species
 * Lesueurilla isabellaensis
 * Lesueurilla kushanensis
 * Lesueurilla louderbacki
 * Lesueurilla magna
 * Lesueurilla prima
 * Lesueurilla shirakii
 * Lesueurilla sinkiangensis
 * Mestoronema P. J. Wagner, 2002
 * Mestoronema bipatellare Koken, 1925 - type species
 * Mestoronema marginalis (Koken, 1925)
 * Mestoronema scotica (Longstaff, 1924)

Description
Fossils of family Lesueurillidae has sharp peripheral band and a short notch formed from deep V-shaped sinus. They are similar to Maclurites but they differ in early ontogenesis from them.