These images are of the holotype fossil of Gennaeocrinus carinatus crinoid. It was named by Elvira Wood a paleontology instructor at the Massachusetts Institute of Technology (MIT) in 1901. The fossil found in the Hamilton Group of Charlestown, Indiana USA. The fossil dates to the Middle Devonian Period. I believe the Hamilton (New York) is compared to the Sellersburg Limestone (Silver Creek and Beechwood limestones).
The Miss Wood observes "This species is remarkable for its elaborate and delicate surface ornamentation, the thin carinae rising at right angles to the surface and sometimes a millimeter or more in height." The genus was named by Wachsmuth and Springer in 1881. The species name appears to be derived from the word "carina" (a keel-like part or ridge, Latin for keel). This holotype specimen now resides at the Museum of Comparative Zoology - Harvard University (Invertebrate Paleontology 108317).
This fossil is the first fossil species she named and would later leave MIT to work with Charles Walcott on Cambrian fossils at the U.S. Geological Survey. Afterwards, she would obtain her Masters and PhD at Columbia University and spend the rest of her career curating at natural history museums and creating paleoart for scientific papers (Columbia University, Museum of Comparative Zoology at Harvard University and American Museum of Natural History in New York).
A new Crinoid from the Hamilton of Charlestown, Indiana by Elvira Wood, American Journal of Science, Vol. XII, October 1901, pp. 1-14. Pl. V. [LINK]