Sowerby family

The Sowerby family was a British family of four generations of naturalists, illustrators, botanists, and zoologists. 
Most of their work was on molluscs and their systematics. Together, they introduced many taxonomic names (sometimes the number 5000 is mentioned). 
All three of the G.B Sowerbys published extensively on the subject of conchology, which is the collection and study of shells. Even for professional taxonomists it is difficult to know which of the three "G.B. Sowerbys" is meant in a particular citation. The numbering system G.B. Sowerby I, II, or III helps. "Sowerby, 1870" can refer to either G.B. Sowerby II or G.B. Sowerby III.