|A shell of Erosaria lamarckii from Zanzibar, anterior end towards the right|
|(unranked):|| clade Caenogastropoda|
| Erosaria lamarckii|
The shells of these common cowries reach on average 37–41 millimetres (1.5–1.6 in) of length, with a minimum size of 18 millimetres (0.71 in) and a maximum size of 51 millimetres (2.0 in). The basic color of the oval-shaped, smooth and shiny shells is ochraceous or fulvous, the dorsum shows a clear longitudinal line and it is ocellated with many whitish small spots, while several chestnut or reddish-brown speckles are present on the edges of both sides. The base is mainly whitish, with a long and wide aperture with several teeth. In the living cowries the mantle is well developed, with external antennae.
This species is distributed in the East Africa and in the Indian Ocean along Aldabra, Kenya, Madagascar, the Mascarene Basin, Mauritius, Mozambique, Zanzibar, Réunion , the Seychelles, Tanzania, India, Thailand, Singapore, Indonesia and Philippines.
Living cowries can be encountered in tropical intertidal water or on coral reef up to about20 metres (66 ft) of depth. As they fear the light, during the day they usually stay in coral caves or under rocks. At dawn or dusk they start feeding on sponges or coral polyps.
- Erosaria lamarckii fainzilberi Lorenz & Hubert, 1993
- Erosaria lamarckii lamarckii (J. E. Gray, 1825)
- Erosaria lamarckii redimita Melvill, 1888
- Verdcourt, B. (1954). The cowries of the East African Coast (Kenya, Tanganyika, Zanzibar and Pemba). Journal of the East Africa Natural History Society 22(4) 96: 129-144, 17 pls.
- Burgess, C.M. (1970) - The Living Cowries. AS Barnes and Co, Ltd. Cranbury, New Jersey
- E.L. Heiman - VARIABILITY OF COWRY POPULATIONS - 21. INTRASPECIFIC VARIATION IN EROSARIA LAMARCKII (GRAY, 1825) Man and mollusk
- 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. page(s): 64