Annulariidae

The family Annulariidae is a taxonomic family of small operculate land snails in the superfamily Littorinoidea.^[1]

(Original description) This family encompasses all New World "Cyclostomoid" mollusks previously classified under the family names Cyclostomatidae or Eriidae.

Key Distinguishing Characteristics: The primary feature that separates this family from all other operculate pulmonates is found in the radula (the rasping tongue), which exhibits a fundamental uniformity across the large number of included species.

Radula Structure

the radula possesses a consistent tooth arrangement:

• Rachidian tooth: single and unicuspid.
• Lateral tooth: single and unicuspid.
• Inner marginal tooth: resembles the lateral tooth in form but is multicuspid.
• Outer Mmrginal tooth: long and curved like a bow (arcuate). It is pectinated (comb-like) on both its recurved edge and its main portion, but these pectinations do not divide it into individual teeth.
• Jaw: absent.

Foot and progression

The sole of the foot is longitudinally divided by a sulcus (groove), which separates it into two muscular masses. These two masses function independently, allowing the animal a method of progression by alternate waves of muscular contraction (first on one side, then on the other). The foot is relatively short.

Head and sensory organs

• Muzzle: a bifid (forked) muzzle of varying length is always present.
• Tentacles: they are long, slender, and either fibrillar or slightly swollen at the ends.
• Eyes: The eyes are situated at the base of the tentacles on the outer side. They are often raised above the surface of the head by a fleshy protuberance.

Operculum

The operculum displays a wide degree of variation across the family's divisions, yet it follows distinct evolutionary lines of progression. The structure ranges from a simple type to a highly complicated one, with intermediate steps easily traceable. All opercula possess a basal chondroid plate (cartilaginous base) upon which calcareous ribs and lamellae (thin plates) are deposited. Modifications of these calcareous structures are used to subdivide the family into a series of subfamilies and genera, as will be discussed below.

Shell

The shell shape varies widely, from depressed helicoid (flat, spiral like a snail) to elongate conic. The surface sculpture varies greatly: from axially ribbed only to axially ribbed and spirally lirate (with fine spiral lines). The intensity of these elements ranges from obsolete (faint) to lamellose (layered/plate-like).^[2]

Subfamily Abbottellinae Watters, 2016

• Abbottella Henderson & Bartsch, 1920
• Abbottipoma Watters, M. L. Smith & Sneddon, 2020
• Annularisca Henderson & Bartsch, 1920
• Arenabbottella Watters, M. L. Smith & Sneddon, 2020
• Lagopoma Bartsch, 1946
• Leiabbottella Watters, 2010
• Meganipha F. G. Thompson, 1978
• Microabbottella Watters, M. L. Smith & Sneddon, 2020
• Opisthosiphon Dall, 1905
• Preclaripoma Watters, M. L. Smith & Sneddon, 2020
• Rolleia Crosse, 1891

Subfamily Annulariinae Henderson & Bartsch, 1920

• Adamsiella L. Pfeiffer, 1851
• Annularia Schumacher, 1817
• Annularops Henderson & Bartsch, 1920
• Blaesospira Crosse, 1891
• Chittypoma Watters, 2006
• Cistulops H. B. Baker, 1924
• Eyerdamia Bartsch, 1946
• Juannularia de la Torre & Bartsch, 1941
• Lugarenia de la Torre & Bartsch, 1941
• Megannularia Watters, 2006
• Saulaepoma Watters, 2006
• Weinlandipoma Bartsch, 1946
• Xenopoma Crosse, 1891
• Xenopomoides de la Torre & Bartsch, 1941

Subfamily Chondropomatinae Henderson & Bartsch, 1920

• Aguayotudora de la Torre & Bartsch, 1941
• Annularodes Henderson & Bartsch, 1920
• Bonairea H. B. Baker, 1924
• Chondropoma L. Pfeiffer, 1847
• Chondrops Bartsch, 1946
• Chondrothyrium Henderson & Bartsch, 1920
• Colonella Bartsch, 1946
• Crossepoma Bartsch, 1946
• Cubadamsiella de la Torre & Bartsch, 1941
• Diplopoma L. Pfeiffer, 1859
• Parachondria Dall, 1905
• Parachondrops Henderson & Bartsch, 1920
• Rhytidopoma Sykes, 1901
• Rhytidothyra Henderson & Bartsch, 1920

Subfamily Rhytidopomatinae Henderson & Bartsch, 1920

• Colonina Bartsch, 1946
• Ramsdenia Preston, 1913

Subfamily Tudorinae Watters, 2006

• Annularita Henderson & Bartsch, 1920
• Articulipoma Bartsch, 1946
• Choanopomops H. B. Baker, 1928
• Chondropomartes Henderson & Bartsch, 1920
• Chondropomella Bartsch, 1932
• Chondropometes Henderson & Bartsch, 1920
• Chondropomium Henderson & Bartsch, 1920
• Chondrothyra Henderson & Bartsch, 1920
• Clydonopoma Pilsbry, 1933
• Colobostylus Crosse & P. Fischer, 1888
• Dallsiphona de la Torre & Bartsch, 1941
• Eutudora Henderson & Bartsch, 1920
• Gouldipoma Watters, 2006
• Gutierrezium de la Torre & Bartsch, 1938
• Halotudora Watters, 2006
• Licina Gray, 1847
• Paradoxipoma Watters, 2014
• Sallepoma Bartsch, 1946
• Samanicola Watters, 2006
• Superbipoma Watters & Larson, 2017
• Tudora Gray, 1850
• Tudorina de la Torre & Bartsch, 1941
• Tudorisca Henderson & Bartsch, 1920
• Turrithyra de la Torre & Bartsch, 1938
• Tessaripoma Watters, 2016
• Incertipoma Bartsch, 1946 (temporary name)

Island of Hispaniola and the Bahama Archipelago.

• Watters, G. Thomas. The Caribbean land snail family Annulariidae: A revision of the higher taxa and a catalog of the species. Backhuys Publishers, 2006.
• Watters, G. Thomas (2014). "A preliminary review of the Annulariidae (Gastropoda: Littorinoidea) of the Lesser Antilles". Nautilus. 128 (3): 65–90.
• Watters, G. Thomas; Larson, Paul (2017). "A revision of the Hispaniolan genera Chondropomella, Chondropomium, and Clydonopoma (Gastropoda: Annulariidae), with the recognition of a new genus, Superbipoma: phylogenetic, radular, and conchological evidence". Nautilus. 131 (3): 163–201.

• Simone, Luiz Ricardo L. (2004). "Comparative morphology and phylogeny of representatives of the superfamily of architaenioglossans and the annulariidae (mollusca, caenogastropoda)". Arquivos do Museu National. 62 (4): 387–504.
• Watters, G. Thomas (2014). "A revision of the Annulariidae of Central America (Gastropoda: Littorinoidea)". Zootaxa. 3878 (4): 301–350. doi:10.11646/zootaxa.3878.4.1. PMID 25544449.