Bartrumella is a small genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of very small sea snail

Snail

Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...

s, pyramidellid

Pyramidellidae

Pyramidellidae, common name the pyram family, or pyramid shells, is a voluminous taxonomic family of mostly small and minute ectoparasitic sea snails, marine heterobranch gastropod molluscs or micromolluscs....

 gastropod mollusks or micromollusk

Micromollusk

A micromollusk is a descriptive term for a shelled mollusk which is extremely small, even at full adult size. The word is usually, but not exclusively, applied to marine mollusks, although in addition, numerous species of land snails and freshwater mollusks also reach adult size at very small...

s in the family Pyramidellidae

Pyramidellidae

Pyramidellidae, common name the pyram family, or pyramid shells, is a voluminous taxonomic family of mostly small and minute ectoparasitic sea snails, marine heterobranch gastropod molluscs or micromolluscs....

 withon the tribe Chrysallidini (sensu taxonomy by Bouchet & Roctroi, 2005).

Etymology

The genus is named after Professor and Mrs. John Arthur Bartrum (1885-1949), of Takapuna, Auckland.

Shell description

The shell of Bartrumella is high spired with a well-developed columellar lamella, which gives the appearance of a tooth in the aperture.

There are axial ribs and fine spiral sculpture in the form of raised intercostal threads which are only visible through a hand lens or microscope

Microscope

A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...

. The spiral sculpture is present on all whorls

Whorl (mollusc)

A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...

 and on the base. This sculpture is stronger towards the apical

Apex (mollusc)

Apex is an anatomical term for the tip of the mollusc shell of a gastropod, scaphopod, or cephalopod mollusc.-Gastropods:The word "apex" is most often used to mean the tip of the spire of the shell of a gastropod...

 side of the whorls, and in that area there are nodules where the spiral and axial sculpture cross. The axial sculpture evanesces gradually on the base. The protoconch

Protoconch

A protoconch is an embryonic or larval shell of some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod...

 is intorted (planorboid).

The original description of the genus and type species can be fond at: http://rsnz.natlib.govt.nz/volume/rsnz_69/rsnz_69_04_004130.html and at http://rsnz.natlib.govt.nz/volume/rsnz_71/rsnz_71_01_001130.html

Life history

Nothing is known about the biology of the members of this genus. As is true of most members of the Pyramidellidae

Pyramidellidae

Pyramidellidae, common name the pyram family, or pyramid shells, is a voluminous taxonomic family of mostly small and minute ectoparasitic sea snails, marine heterobranch gastropod molluscs or micromolluscs....

 sensu lato, they are most likely to be ectoparasites.

Species

Species within the genus Bartrumella include:

• Bartrumella kaawaensis Laws, 1940 - type species
• Bartrumella waitakereensis

External links

• Bartrumella kaawaensil illustration of type species