Aspidonia organisms historical artwork, 1904

Caption: Aspidonia organisms. Historical artwork of Aspidonia organisms, a now invalid name for a grouping of the classes Merostomata and Trilobita. Many of these organisms are now extinct, except for four belonging to the class Merostomata. This artwork was by Ernst Haeckel and was the 47th plate from his Art Forms in Nature, published in 1899.  References: SCIENCE PHOTO LIBRARY.  See here for index to numbers.

1. Limulus moluccanus (Clusius) = Tachypleus gigas (Müller, 1785), adult male from above
2. Limulus moluccanus (Clusius) = Tachypleus gigas (Müller, 1785), adult male from below
3. Limulus moluccanus (Clusius) = Tachypleus gigas (Müller, 1785), larva
4. Eurypterus Fischeri (Eichwald) = Eurypterus tetragonophthalmus (Fischer, 1839) / Baltoeurypterus tetragonophthalmus (Fischer, 1839), from above
5. Pterygotus anglicus (Agassiz) = Pterygotus anglicus Agassiz, 1844, from above
6. Trinucleus Goldfussi (Barrande) = Onnia goldfussi (Barrande, 1846), from above
7. Deiphon Forbesi (Barrande) = Deiphon forbesi Barrande, 1850, from above
8. Phacops latifrons (Bronn) = Phacops latifrons (Bronn, 1825), curled-up individual (8a: from forward, 8b: from the side)
9. Dalmania punctata (Barrande) = Asteropyge punctata (Steininger, 1831), from above
10. Ampyx Rouaulti (Barrande) = Raphiophorus rouaulti (Barrande, 1852), from above
11. Paradoxides bohemicus (Boeck) = Paradoxides bohemicus (Boeck, 1828), from above
12. Cheirurus insignis (Beyrich) = Cheirurus insignis Beyrich, 1845, from above
13. Acidaspis Dufresnoyi (Barrande) = Selenopeltis buchi (Barrande 1846), from above
14. Megalaspis extenuatus (Angelin) = Megistaspidella extenuata (Wahlenberg, 1821), from above
15. Harpes ungula (Sternberg) = Bohemoharpes ungula (Sternberg, 1833) (15a: from above, 15b: from the side)
16. Agnostus pisiformis (Linné) = Agnostus pisiformis (Linnaeus, 1757), from above
17. Lichas palmata (Barrande) = Trochurus speciosus Beyrich, 1845, from above
18. Hydrocephalus saturnoides (Barrande) = Eccaparadoxides pusillus (Barrande, 1846) / Phanoptes pusillus (Barrande, 1846), from above
19. Sphaerexochus mirus (Beyrich) = Sphaerexochus mirus Beyrich, 1845, fron the side
20. Triarthrus Becki (Beecher) = Triarthrus becki Green 1832 (20a: from above, 20b: from below) - Autor: Kunstformen der Natur (1904), plate 47: Aspidonia (see here, here, here and here) - Year: 1904