Hypodicranotus

Hypodicranotus striatulus is an extinct, pelagic trilobite in the order Asaphida, of the family Remopleuridae. Its fossils are found in Middle Ordovician-aged marine strata in New York State, United States, and in Ontario, Canada.
The dorsal exoskeleton of "H. striatulus" is very similar to the related genus, "Remopleurides", but, "H. striatulus" has a comparatively enormous, forked hypostome.