An arrangement labelled as Actinosphenia from Santa Monica. Prepared by Arthur Cottam. These are Actinoptychus (I am assuming Actinosphenia is an old name). The ones on the left and right look to be Actinoptychus vulgaris, and the one in the middle Actinoptychus glabratus (perhaps var. incisa) which reflects the pencil writing on the label. 40x Leitz Pl Apo NA 1.00 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, slightly oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 69 images stacked in Zerene (Pmax).