Illustration of Cothonion
Invertebrate Palaeontology and Evolution By E. N. K. Clarkson
https://books.google.com/books?id=ozNIDAAAQBAJ&pg=PT231&lpg=PT231&dq=Cothonion&source=bl&ots=Chv9K4NFIo&sig=Pl2D4h37Lhl7pKeERWBG8k9YmAY&hl=en&sa=X&ved=2ahUKEwipzuDgzOnfAhUjjoMKHcJWBT44ChDoATAJegQICBAB
