Diagnosis
The female lacks a rostrum. The carapace is highly ornamented with ridges and pores. The fine hairs on the carapace have simple endings. Both sexes have well-developed lateral eyes. Each lamella of the caudal furca carries five hook setae, only the first of which is fused to the lamella.
Remarks
There are currently 55 species in this genus, the majority of which are shallow-living neritic species. Just two have been reported from the area, the type species S. capsula, and recently an exotic species S. zostericola has been reported to have been introduced into the estuarine waters of South-east England with transplanted oysters (Kornicker, 1975b).