Ok, it's taking up most of the picture. I believe this is a Sharpnose Crab (Scyra acutifrons). I saw one in Seattle in Jan, but this is my first one in CA.
Wissenschaftliche Ergebnisse der Deutschen Tiefsee-Expedition auf dem Dampfer "Valdivia" 1898-1899. bd.6. AtlasJena,G. Fischer,1902-40.biodiversitylibrary.org/page/6307582
Paramithrax longipes, now Leptomithrax longipes Identifier: s7annalsmagazine10londuoft (find matches)Title: The annals and magazine of natural history : zoology, botany, and geologyYear: 1838 (1830s)Authors: Subjects: Natural historyPublisher: London : Taylor & FrancisContributing Library: Gerstein - University of TorontoDigitizing Sponsor: University of TorontoView Book Page: Book ViewerAbout This Book: Catalog EntryView All Images: All Images From Book Click here to view book online to see this illustration in context in a browseable online version of this book.Text Appearing Before Image:to the orals on a thin unplatcdmembrane stretching like the web of a ducks foot between eacharm and the tegmen. The name Geplujrocrinus is suggested bythis resemblance to a suspension bridge. Minor points of distinc-tion from Hi/ocrinus are the fusion of the basals, the greater thicknessof the cup-plates, the almost complete atrophy of the ambulacrals,and the form of the pinnules, which have not the peculiar arrange-ment characteristic of Hyocrhms. These diflPerences have inducedthe authors to give a fresh diagnosis of the Hyocrinidae, differingconsiderably from that in the Challenger Report. Although the unique specimen of G. Grimcddn is small, some-what imperfect, and naturally cannot be sacrificed for minutedissection, it has been found possible to give a very exact descriptionof all the details of its external anatomy. These have suggested toone of the authors a renewed investigation of the type of Hi/ocrinusBetJiellianus, with results that may be published more fully else-where.Text Appearing After Image:Note About Images Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.
(Photographs by SE Anosov) Spiridonov VA, Simakova UV, Anosov SE, Zalota AK, Timofeev VA (2020) Review of Macropodia in the Black Sea supported by molecular barcoding data with the redescription of the type material, observations on ecology and epibiosis of Macropodia czernjawskii (Brandt, 1880) and notes on other Atlanto-Mediterranean species of Macropodia Leach, 1814 (Crustacea, Decapoda, Inachidae). Zoosystematics and Evolution 96(2): 609-635. https://doi.org/10.3897/zse.96.48342
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Figure 10; Natural habitats of Macropodiz czernjawskii in the Black Sea. a, b. Male (ZMMU Ma 3549) in Cystoseira sp., on rock, Tuaphat coastal rock masif, near Gelendzhik. c. Male (ZMMU Ma 3547), on sand, of Blagoveschenskaya village, near Anapa. d. Specimen collected of Blagoveschensakya in aquarium, decorated with red algae after few days of keeping. e. A characteristic biotope of M. czernjawskii in Tuaphat. f. Biotope in Kazachya Cove, Crimean Peninsula where M. czernjawskii has been repeatedly observed. Photographs by SE Anosov.