Lomita strew slides, Barry Pemberton

Auliscus caelatus (?)
Cocconeis pseudomarginata (?)
Navicula oswaldii (?)
Hemidiscus cuneiformis (?)
Unknown (Thalassiosira sp. ?)
Navicula lyra var. elliptica (?)
Stephanogonia sp. (?)
Stictodiscus buryanus (?)
Auliscus punctatus (?)
Eupodiscus californicus f. bioculata
Navicula californica (?)
Actinoptychus glabratus var. incisa (?)
Campyloneis grevillei var. argus
Cocconeis dirupta (?)
Lomita strew, 10x Nikon Plan Apo NA 0.45 objective
Example strew slide

Images from 5 fossil strew slides from Lomita, California. Prepared by Barry Pemberton. Mounted in Zrax and made in June 2024. I have spent some time trying to identify these based on a couple of documents (Schmidt’s Atlas of course, and “The Santa Monica Diatomaceous Deposit with List of References to Figures of Species”, E. A. Schultze and C. Henry Kain, Bulletin of the Torrey Botanical Club , Nov. 30, 1897, Vol. 24, No. 11 (Nov. 30, 1897), pp. 496-504 and with the assistance of a couple of experts. Anything I am not sure about has a question mark after it, and as always I welcome comments to help with correcting any mistakes. One I have described as ‘unknown’. After discussion with a few people, it could be a Thalassiosira, perhaps T. punctigera.

Some very nice specimens, in fairly good state of preservation.

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. Images stacked in Zerene (Pmax).