Polygyridae

Taxobox
name = Polygyridae

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image_width = 200px
image_caption = "Mesodon thyroidus" from W. G. Binney, 1878 [Binney, William G. (1878). The Terrestrial Air-Breathing Mollusks of the United States and Adjacent Territories of North America. Vol. 5 (plates). Bull. Mus. Comparative Zool., Harvard. Plate 11.]
regnum = Animalia
phylum = Mollusca
classis = Gastropoda
ordo = Pulmonata
subordo = Eupulmonata
infraordo = Stylommatophora
parvordo = Sigmurethra
superfamilia = Helicoidea
familia = Polygyridae
familia_authority = Pilsbry, 1895
subdivision_ranks = Genera
subdivision =
"see text"

Polygyridae is a family of air-breathing land snails, terrestrial pulmonate gastropod mollusks.

The Polygyridae make up a significant proportion of the land snail fauna of eastern North America, and are also found in western North America, northern Central America, and are present on some Caribbean islands. The definitive reference to the group is Henry Pilsbry's 1940 monograph. Pilsbry, Henry A. 1940. Land Mollusca of North America (North of Mexico). Acad. Nat. Sci. Philadelphia, Monograph 3, vol. 1(2): 575-994.]

This snail family is distinguished from other gastropods on the basis of several anatomical features. They have no dart apparatus - a portion of the reproductive system in some snails and slugs which deals with the calcareous "darts" used for reproductive stimulation; the muscles which allow the eyes and pharynx to be retracted united into a single band; and the jaws are ribbed. [Pilsbry, Henry A. 1939. Land Mollusca of North America (North of Mexico). Acad. Nat. Sci. Philadelphia, Monograph 3, vol. 1(1): 1.]

Genera

Pilsbry uses the generic names "Allogona", "Ashmunella", "Giffordius", "Mesodon", "Polygyra", "Praticolella", "Stenotrema", "Trilobopsis", "Triodopsis", and "Vespericola". The remaining names listed here have either been elevated from Pilsbry's subgenera, since 1940, or newly created. The two subfamilies, Polygyrinae and Triodopsinae, are distinguished on the basis of reproductive anatomy. [Pilsbry, Henry A. 1940. Land Mollusca of North America (North of Mexico). Acad. Nat. Sci. Philadelphia, Monograph 3, vol. 1(2): 576.] [Emberton, K.C. 1991. The genetic, allozymic and conchological evolution of the tribe Mesodontini. Malacologia 33 (1-2): 71-178] [ [http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=77429] Polygyridae at ITIS (Integrated Taxonomic Information System); accessed 18 Dec. 2007.]

Subfamily Polygyrinae Pilsbry, 1940:
* "Appalachina"
* "Daedalochila"
* "Euchemotrema"
* "Fumonelix"
* "Giffordius"
* "Hochbergellus"
* "Inflectarius"
* "Linisa"
* "Lobosculum"
* "Mesodon"
* "Millerelix"
* "Patera"
* "Polygyra"
* "Praticolella"
* "Stenotrema"
* "Trilobopsis"

Subfamily Triodopsinae Pilsbry, 1940:
* "Allogona"
* "Ashmunella"
* "Cryptomastix"
* "Neohelix"
* "Triodopsis"
* "Vespericola"
* "Webbhelix"
* "Xolotrema"

According to the Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005) this family consists of the following subfamilies and tribes :
*Subfamily Polygiriniae Pilsbry, 1895
** tribe Allogonini Emberton, 1995
** tribe Ashmunellini Webb, 1954
** tribe Polygyrini Pilsbry, 1895
***subtribe Mesodontina Tryon, 1866
*** subtribe Polygyrina Pilsbry, 1895
*** subtribe Stenotrematina Emberton, 1995
*Subfamily Triodopsinae Pilsbry, 1940

References

Photos of polygyrids