Bird’s Hill strew, Maryland, Steve Edgar

Bird’s Hill strew, 10x Nikon Plan Apo NA 0.45 objective
Stephanogonia actinoptychus
Craspedodiscus coscinodiscus
Actinoptychus senarius

A strew slide from Bird’s Hill, Maryland. The Meakin Collection 2005. Prepared by Steve Edgar. Mounted in Pleurax. Wide range of species present, including Stephanogonia actinoptychus, Craspedodiscus coscinodiscus and Actinoptychus senarius (all ID’s done by me, so should be considered tentative). Olympus BHB microscope using 450nm LED light. 63x Leitz Pl Apo NA 1.40 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, brightfield lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. Stacks prepared in Zerene (Pmax).

The Bird’s Hill location is mentioned in “Arachnoidiscus in Maryland Diatomaceous Earth”, Blanton C. Welsh, Transactions of the American Microscopical Society, Vol. 34, No. 4 (Oct., 1915), pp.290-291 (

“The deposit, a part of the Maryland Miocene, of which the Richmond beds form a part, is at a point known as Bird’s Hill on the State Road about nine miles south of Annapolis. At this place is about one hundred feet above sea level and is the highest point I know of at which this earth shows. The deposit is only a few feet above sea level at Ferry Landing opposite Nottingham and at the Calvert Cliffs on the Chesapeake Bay, both these latter places being about twenty-five miles south of Bird’s Hill.”.