CLASS CEUSTAOEA. 



FAMILY ACIDASPIDiE.— Acidaspis, Terataspis. 



FAMILY AGLASPID^.— Aglaspis. 



FAMILY AGXOSTID.E.— Agnostus, Shumardia. 



FAMILY ASAPHIDjE. — Asaphus, Bathyurellus, Bathyurus, Dolichometopus, Illfenus, 



Illaenurus, Isotelus, Megalaspis, Nileus, Ogygia. 

 FAMILY BRONTEIDyE.-Bronteus. 



FAMILY' CALYMENID^.— Arges, Calymene, Homalonotus. 

 FAMILY CERAURID^. — Amphion, Ceraurus, Encrinurus, Sphserexochus. 

 FAMILY CONOCEPHALID^.— Conocephalites, Conocoryphe, Crepicephalus, Dicello- 



cephalus, Ptychaspis, Solenopleura. 

 FAMILY CYPHASPID^.— Cyphas. 



FAMILY CYTHERID^.— Cythere, Cytherina, Cytheropsis. 



FAMILY EURYPTERID^.— Anthraconectes, Dolichopteris, Eurypterus, Pterygotus. 

 FAMILY HARPEDIDiE.— Harpes, Harpides. 



FAMILY LEPERDITIIDjE.— Beyrichia, Isochilinia, Leperditia, Primitia. 

 FAMILY LICHASIDtE.— Lichas. 

 FAMILY PARADOXIDjE, — Agraulos, Anapolenus, Arionellus, Bathyn<?tus, Chario- 



cephalus, Loganellus, Menocephalus, Olenellus, Olenus, Paradoxides, Remopleu- 



rides, Telephus, Triarthrella, Triarthrus. 

 FAMILY PHACOPIDjE.— Dalmanites, Phacops, Thaleops. 



FAMILY PROETID.E.— Phillipsia, Prcetus. [cleus. 



FAMILY TRINUCLEIDjE. — Ampyx, Endymionia, Holometopus, Microdiscus, Trinu- 

 ORDER AMPHIPODA.— Diplostylus. 

 ORDER CIRRHOPODA.— Plumulites. 

 ORDER ISOPODA.— Acanthotelson. 



ORDER MACRURA. — Anthracopala;mon, Archseocaris, Palieocaris. 

 ORDER PHYLLOPODA. — Ceratiocaris, Dithyrocaris, Leaia, Solenocaris. 

 ORDER STOMAPODA.— Amphipeltis. 

 ORDER XYPHOSURA.— Euproops. 

 INCERTiE SEDIS.— Climachtichnites, Diplichnites, Helminthoidichnites, Protichnites, 



Rusichnites. 



AcantJwloma, syn. for Acidaspis. 



spinosa, syn. for Acidaspis tuberculata. 

 Acanthotelson, Meek & Wortlien, 1860, 



Proc. Acad. Nat. Sci. [Ety. akantha, 



a spine; tehon, tlie end.] 

 eveni, Meek & Worthen, 1868, Am. Jour. 



Sci., vol. 46, Coal Meas. [Ety. proper 



name.] 

 inxqualii, syn. for Pateocaris typus. 

 stimpsoni, Meek & Worthen, 1865, Proc. 



Acad. Nat. Sci., Coal Meas. [Ety. 



proper name.] 



Acidaspis, Murchison, 1839, Sil. Syst. [Ety. 



akis, a spear-point ; a»pis, a shield.] 

 anchoralis, S. A. Miller, 1875, Cin. Quar. 



Jour. Sci., Cin. Gr. [Sig. anchor-like.] 

 ceralepta, Anthony, 1838, (Ceratocephala 



ceralepta) Am. Jour. Sci., Cin'ti Gr. 



Not clearly defined, 

 f.cincinnatiensis. Meek, 1873, Ohio Pal., 



vol. 1, Cin'ti Gr. [Ety. proper name.] 

 crosotus, Locke, 1843, Am. Jour. Sci., vol. 



44, Cin'ti Gr. [Ety. crossotos, fringed.] 



The word is misspelled — it should he 



crossota. 



