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Show 1042 DR. J. W. GREGORY ON THE CLASSIFICATION [Dec. 15, Synopsis of Classification. Class STELLEROIDA. Subclass OPHIUEOIDEA. Order I. Lysophiurae.-Ambulacral ossicles alternate, free. No ventral arm-plates. Fam. 1. PROTASTERIDAE. Boot-shaped ambulacral ossicles. Genera.-Protaster, Forbes. Bundenbachla, Stiirtz. Fam. 2. PALJEOPniURiDiE. Long bar-shaped ambulacral ossicles. Genera.-Sturtzura, Greg. Palceophiura, Stiirtz. Tceniura, Greg. Eugaster, Hall. Ptilonaster, Hall. Order II. Streptophiurae. Vertebral ossicles present, with more less Streptospondyline articulations Fam. 1. OPHIURINID^. Ambulacral ossicles slightly united and no ventral arm-plates. Genera.- Ophlurlna, Stiirtz. Tremataster, Worth. & Mill. Fam. 2. LAPWORTHURIDJE. Ambulacral ossicles fused. No ventral arm-plates. Madreporite dorsal. Genera.-Lapworthura, Greg. Furcaster, Stiirtz. Palastropecten, Stiirtz. Fam. 3. EOLUIDID^;. Vertebral ossicles. Ventral arm-plates, but no buccal shields. Genera.-Eoluldla, Stiirtz. Eospondylus, Greg. Miospondylus, Greg. Aganaster, Mill. & Gurl. Cholaster, Worth. & Mill. Fam. 4. ONYCHASTERID^E. Contorted unbranched arms. Integument granular. Genus.-Onychaster, Meek & Worth. Fam. 5. EUCLADIID^E. Contorted branched arms. Integument granular. Genus.-Eucladia, H. Woodw. |