TRIMUSCULIDAE are a small family of marine pulmonates, formerly grouped in the GADINIIDAE J. E. Gray, 1840 and earlier confused with members of the much larger pulmonale family SIPHONARIIDAE. There are three genera regularly used: Gadinia, Gadinalea and Trimusculus. However, differences between species placed in these generic taxa are conchologically not recognizeable and the majority of authors use Trimusculus only. A quick search in the literature shows the following species and distribution: Europe & West Africa
Trimusculus mammillaris (Linnaeus, 1758)
Trimusculus afer (Gmel in, 1791) South Africa
Trimusculus costatus (Krauss, 1848) Caribbean & west Atlantic
Trimusculus goesi (Hubendick, 1946)
Trimusculus carinatus (Dall, 1870)
South and west coast of America
Trimusculus peruvianus (Sowerby II. 1835) Trimusculus reticulatus (Sowerby II. 1 835) Trimusculus stellatus (Sowerby II, 1835)
Australia & New Zealand
Trimusculus conicus (Angas,l 867) Trimusculus nivea (Hutton, 1883)
Polynesia
Trimusculus odhneri (Hubendick. 1946)
Japan
Trimusculus kurodai Habe, 1958 Trimusculus yamamotoi Habe, 1958