Zanthopsis bispinosa is one of the species of crab found in the London Clay.
Xanthopsis bispinosa is an old name for Zanthopsis bispinosa.
An example of Zanthopsis bispinosa can be seen below, it carapus can be seen in great detail.
Kingdom: Animalia
Phylum: Arthropoda
Class: Malacostraca
Order: Decapoda
Family: Zanthopsidae
Genus: Zanthopsis
Species: Zanthopsis bispinosa
Image taken from Tony Mitchell's Database with Tony Mitchell's help and permission.
Fossil from Fred Clouter's collection.
Diagram from: XIX.—On the classification of some British Fossil Crustacea, with notices of new forms in the University Collection at Cambridge
Acknowledgments:
Thank you very much Tony Mitchell for allowing usage of an image on this page.
References:
https://www.mindat.org/taxon-8611852.html