Amphicyclotulus amethystinus

Amphicyclotulus amethystinus is a species of tropical land snail with a gill and an operculum, a terrestrial gastropod mollusc in the family Neocyclotidae.^[3]

Amphicyclotulus amethystinus
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Caenogastropoda
Order:	Architaenioglossa
Superfamily:	Cyclophoroidea
Family:	Neocyclotidae
Genus:	Amphicyclotulus
Species:	A. amethystinus
Binomial name
Amphicyclotulus amethystinus (Guppy, 1868)[1]
Synonyms[2]
Cyclotus amethystinus var. α Guppy, 1868 (in part) Cyclotus amethystinus var. β Guppy, 1868 Cyclophorus schrammi (Shuttleworth) Amphicyclotulus mineri Bartsch, 1942 Amphicyclotulus (Amphicyclotulus) mineri Bartsch in Torre, Bartsch & Morrison, 1942 Cyclophorus amethystinus Amphicyclotulus (Cycloblandia) amethystinus

Shell description

The shell is smooth, shining, not striate spirally, generally somewhat more depressed, deep chestnut or reddish brown. Whorls are a little flattened near the suture.^[1] The species may have subtle spiral striation, although there exists considerable variation; axial growth lines are clearly visible.^[2]

The operculum is horny, diaphanous, concave externally, cartilaginous within, the nucleus projecting internally; with from ten to fourteen very narrow whorls, their rather lamellar outer edges slightly free.^[1]

Amphicyclotulus amethystinus has spiral threads absent or only weakly present.^[2] There are found only two species in the genus Amphicyclotulus in Dominica. The other species is Amphicyclotulus dominicensis and it has spiral cords clearly present and raised.^[2]

Apical view of the shell. Width of the shell is 14.1 mm.

Apical view of the shell. Width of the shell is 18.4 mm.

Robert John Lechmere Guppy (1868)^[1] noted that this species is not found above 1000 m. Although he recognized two "forms", he did not recognize two separate species. George French Angas (1884)^[4] subsequently recorded "Cyclophorus amethystinus" from altitudes above 1200 m. Paul Bartsch (1942)^[5] restricted the name amesthystinus to Guppy’s var. β, the "smooth, shining, not striate spirally" form.^[2]

Distribution

Distribution of Amphicyclotulus amethystinus (green dots) and Amphicyclotulus dominicensis (one blue dot) in Dominica.

This species is endemic to in Dominica.^[2]

The type locality is Laudat, Dominica.^[2] The holotype is in National Museum of Natural History under number 535856.^[2]

All known localities of Amphicyclotulus amethystinus include:^[2]

• Saint Andrew Parish, Dominica: west of Calibishie, Hampstead Estate
• Saint Andrew Parish, Dominica: Carib Territory
• Saint Andrew Parish, Dominica: Marigot, Captain Bruce
• Saint Andrew Parish, Dominica: 1 km northwest of Thibaud
• Saint David Parish, Dominica: Emerald Pool
• Saint David Parish, Dominica: 1.5 km north of Petit Savane
• 0.5 km south of Rosalie River bridge
• Saint George Parish, Dominica: Bellevue Chopin
• Saint George Parish, Dominica: Freshwater Lake area
• Saint George Parish, Dominica: trail to Lake Boeri
• Saint Joseph Parish, Dominica: d’Leau Grommier
• Saint Joseph Parish, Dominica: road to Fond Cassé, Mary Martin Farm
• Saint Joseph Parish, Dominica: path Mero-Salisbury
• Saint Luke Parish, Dominica: Pointe Michel
• Saint Paul Parish, Dominica: Sylvania
• Saint Peter Parish, Dominica: Syndicate.