helgolandica

	site	site # (info)	collection date	kind	depth	substrate	salin	comments	reference
A	north harbor (Nordhafen), Helgoland Island, Germany	668 map	Jul 1964	type locality	32-33 m	coarse sand		museum specimen number: SMF 3331-34	Dorjes J (1968): 365; also biogeography and ecology on this and other German Bay species in (citation)- 78-115.
B	north flat (Nordwatt), Helgoland Island, Germany	726 map	Oct 1964			shell		museum specimen number: SMF 3331-34	Dorjes J (1968): 365; also biogeography and ecology on this and other German Bay species in (citation)- 78-115.