Search for: [Subject and Keywords = Insects, \- bee \(Sphecodes \- Halictidae\) \- description of species \- North Sea] OR [Subject and Keywords = Owady \- pszczoła \(Sphecodes \- Halictidae\) \- opis gatunków \- morze Północne] OR [Title = Ueber Sabulicola Cirsii mihi] OR [Creator = Verhoeff, Carl Wilhelm \(1867–1944\)]