Architectonica modesta

Architectonica modesta
Shell of Architectonica modesta
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Family:	Architectonicidae
Genus:	Architectonica
Species:	A. modesta
Binomial name
Architectonica modesta (Philippi, 1849)
Synonyms
Architectonica perspectiva var. modesta(R. A. Philippi, 1849) superseded rank Solarium modestumR. A. Philippi, 1849 superseded combination

Architectonica modesta, the giant sundial, is a species of sea snail, a marine gastropod mollusk in the family Architectonicidae, which are known as the staircase shells or sundials. ^[1]

Description

(Original description in Latin) The shell is conical, ashy-tawny, and marked with brown zones. The whorls are somewhat convex and are bisulcate (two-grooved) superiorly. The uppermost girdle is white and crenulated, while the second one is brown. The two lowest girdles are divided by an elevated ridge (lira); the upper of these is brown, and the lowest is white. The shell is painted with crowded, yellow, and somewhat obsolete radiating lines. The base is flat and ashy. The umbilicus is equal to two-thirds of the body whorl and is encircled by large white crenations.

The shell contains 7 whorls. The upper whorls are radiately incised, as is usual. A crenulated zone is also apparent on the body whorl. This uppermost zone is milky (or milk-white), and it appears crenulated, being sprinkled here and there with obsolete rusty spots. There is an elevated ridge (lira) between the marginal girdle and the penultimate girdle of the base. The crenations of the umbilicus number about 20. ^[2]

Distribution

This species can be found in the tropical Indo-Pacific, from East Africa and the Persian Gulf to western Pacific, Japan, Australia (Northern Territory, Queensland, Western Australia).

References

1. Architectonica modesta (R. A. Philippi, 1849) . 11 November 2025. Retrieved through: World Register of Marine Species .
2. Philippi, R.A. (1849). "Centuria tertia testaceorum novorum". Zeitschrift für Malakozoologie. 5 (10): 171. Retrieved 11 November 2025. This article incorporates text from this source, which is in the public domain .

• Hanley, S. 1863. Monograph of the recent species of the genus Solarium of Lamarck. 227–246, pls 250–254 in Sowerby, G.B. (ed). Thesaurus Conchyliorum, or Monographs of Genera of Shells. London : Sowerby Vol. 3.
• Marshall, W.B. 1887. Monograph of the family Solariidae. pp. 3-32, pls 1–6 in Tryon, G.W. (ed.). Solariidae, Ianthinidae, Trichotropidae, Scalariidae, Cerithiidae, Rissoidae, Littorinidae. Manual of Conchology. Philadelphia : G.W. Tryon Vol. 9 488 pp., 71 pls.
• Garrard, T.A. 1977 [1978]. A revision of Australian Architectonicidae (Gastropoda: Mollusca). Records of the Australian Museum 31(13): 506–584
• Hinton, A.G. 1979. Guide to shells of Papua New Guinea. Port Moresby, P. N. G. : Robert Brown & Associates 5 pp text, 69 pls, 1 map.
• Springsteen, F.J. & Leobrera, F.M. 1986. Shells of the Philippines. Manila : Carfel Seashell Museum 377 pp., 100 pls.
• Bieler, R. (1993). Architectonicidae of the Indo-Pacific (Mollusca, Gastropoda). Abhandlungen des Naturwissenschaftlichen Vereins in Hamburg. NF. 30: 1–376.
• Drivas, J. & Jay, M. (1988). Coquillages de La Réunion et de l'Île Maurice. Collection les beautés de la nature. Delachaux et Niestlé: Neuchâtel. ISBN 2-603-00654-1. pp. 1–160.
• Steyn, D.G. & Lussi, M. (1998) Marine Shells of South Africa. An Illustrated Collector's Guide to Beached Shells. Ekogilde Publishers, Hartebeespoort, South Africa, ii + 264 pp.
• Steyn, D. G. & Lussi, M. (2005). Offshore shells of southern Africa: A pictorial guide to more than 750 gastropods. Published by the authors. pp. i–vi, 1–289.