Cerastidae is a family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 of air-breathing land snail

Land snail

A land snail is any of the many species of snail that live on land, as opposed to those that live in salt water and fresh water. Land snails are terrestrial gastropod mollusks that have shells, It is not always an easy matter to say which species are terrestrial, because some are more or less...

s, terrestrial

Terrestrial animal

Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...

 pulmonate gastropod mollusks.

Taxonomy

The Cerastidae family is classified within the informal group Orthurethra

Orthurethra

Orthurethra is a clade of terrestrial pulmonate gastropods .In the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005, Orthurethra is treated as an informal group and subclade of Stylommatophora.- Taxonomy :...

, itself belonging to the clade

Clade

A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...

 Stylommatophora

Stylommatophora

Stylommatophora is a taxon of air-breathing land snails and slugs, terrestrial pulmonate gastropod molluscs. This taxon is currently considered to be a clade. It was previously regarded as an infraorder...

 within the clade Eupulmonata

Eupulmonata

The Eupulmonata is a taxonomic clade of air-breathing snails. The great majority of this group are land snails and slugs, but some are marine and some are saltmarsh snails that can tolerate salty conditions.-Linnean taxonomy:...

 (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005

Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005)

The taxonomy of the Gastropoda as it was revised by Philippe Bouchet and Jean-Pierre Rocroi is currently the most up-to-date overall system for classifying gastropod mollusks...

).

The family Cerastidae has no subfamilies.

Genera

Genera in the family Cerastidae include:

• Cerastus Martens, 1860 - type genus of the family Cerastidae
• Pachnodus
  Pachnodus
  Pachnodus is a genus of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Cerastidae.-Species:Species within the genus Pachnodus include:subgenus Pachnodus* Pachnodus becketti Gerlach, 1994...
  
  Martens, 1860
• Rhachistia
  Rhachistia
  Rhachistia is a genus of pulmonate land snail, a gastropod mollusk in the family Cerastidae.Genus Rhachistia is distributed in Eastern Africa and Asia.- Species :Species in the genus Rhachistia include:...
  
  Connolly, 1922
• Rhachis
  Rhachis
  Rhachis is a genus of land snail, gastropod in the Cerastidae family.- Species :It contains the following species:* Rhachis comorensis* Rhachis sanguineus...
  
  Pfeiffer, 1856

Description

Anatomically speaking, there is no flagellum

Flagellum

A flagellum is a tail-like projection that protrudes from the cell body of certain prokaryotic and eukaryotic cells, and plays the dual role of locomotion and sense organ, being sensitive to chemicals and temperatures outside the cell. There are some notable differences between prokaryotic and...

 in the reproductive system

Reproductive system of gastropods

The reproductive system of gastropods varies greatly from one group to another within this very large and diverse taxonomic class of animals...

 of snails in the family Cerastidae, and this is what distinguishes this family from its sister group the family Enidae

Enidae

Enidae is a family of air-breathing land snails, terrestrial pulmonate gastropod mollusks.- Anatomy :In this family, the number of haploid chromosomes lies between 21 and 25 .- 1998 taxonomy :...

.